Kirsty Wigglesworth / AP

Donald Trump has claimed Boris Johnson as his bumbling, blond-haired mini-me from across the water. The U.K. Labour Party is doing all it can to push the same message ahead of next month’s general election, claiming there is a Trump-Johnson alliance afoot. Even Hillary Clinton has criticized the British prime minister for his refusal to publish a report into Russia’s involvement in the Brexit referendum.

And yet, by any serious audit of the two men and what they represent, it is not Boris Johnson who is Britain’s Trump. It’s Jeremy Corbyn.

Take away Brexit, and Johnson is a run-of-the-mill conservative whose policy agenda, instincts, and world view, as opposed to his personality, verge on the dull; a member and defender of the establishment whose wish is to climb atop it, not rip it down. Corbyn is the opposite: a populist who believes in the inherent corruption of the established order, at home and abroad; a man who sees conspiracy and injustice everywhere. Only one of these descriptions comes close to the U.S. president.

The parallels are not immediately obvious. They are hidden beneath their contrasting personalities and values. Corbyn, the Labour Party leader, who is seeking to replace Johnson as prime minister in the December 12 election, is a jam-making vegetarian socialist and self-proclaimed anti-imperialist defender of minority rights. Above all, he is an uncompromising moralist. Trump is none of these things: Even his supporters would be wary of describing him as a moral puritan. Or even moral.

On this scoresheet, Johnson is more Trumpian than Corbyn. The Conservative Party leader is in favor of getting rich; he is also reflexively pro-American (even pro-imperial). In contrast to Corbyn, he is also a moral gymnast, both personally and professionally. Johnson’s critics say he cannot be trusted, that he fibs without remorse—and, like Trump, this appears to do little to dent his supporters’ trust. “He lies and cheats, but I trust him,” as one veteran Conservative campaign official described to me the sentiment among his supporters. Brexit, like Trump’s “America first” agenda, is an exercise in national sovereignty—to make Britain Great Again. So far, so Trump.

But what do Johnson and Corbyn represent at their core? What drives them? And why do their supporters love them so? Here is where the surface Johnson-Trump comparisons fray, revealing the more profound Corbyn-Trump similarities.

Corbyn is a populist who wants to remake his country and change the way it behaves in the world—just like Trump. He is skeptical of the institutional security structures put in place by Britain and the United States after World War II—like Trump. And he’s instinctively hostile to Britain’s closest allies and dovish toward its closest enemies. You get the point.

By comparison, Johnson is boring. He supports multilateral action to tackle climate change, the resurrection of the Iranian nuclear deal, NATO, the “special relationship” with America, Israel’s right to self-defense, military intervention in the Middle East and other regions where necessary, the fabled “rules-based international order,” and so on and so forth. He supports every strand of Britain’s postwar consensus—apart from EU membership. (In contrast, Trump appears to challenge much of that same consensus.)

Here it’s worth quickly examining Brexit. Whether or not he’s correct, Johnson believes Brexit is necessary for the U.K. to become a more dynamic free market and international economy. He wants Britain to pursue more free-trade deals, not fewer, and to lower tariffs, rather than impose new ones. This might not be the effect of Brexit, nor even, some would argue, the intention of its supporters, but it’s the intention of its political masters—and certainly Johnson. Corbyn, in contrast, is a skeptic of all free trade, whether with Europe or the U.S. At heart, Trump is a mercantilist who believes in tariffs (“I love tariffs”) and their effectiveness as an instrument of American power in pursuit of more advantageous trade agreements. Johnson is a Reaganite. In this philosophical battle, Corbyn is much closer to Trumpian protectionism.

Dig deeper, beyond the Trump and Corbyn policy platforms, and what are the two men’s instincts? Trump, his critics allege, is instinctively authoritarian, uncomfortable with dissent and the messy compromises of governing in a democratic system with partially autonomous bureaucracies often vying for control. Like Corbyn, he derives his power from the masses, not through institutions with checks and balances moderating the changes he wants to make, frustrating his program and limiting its scope. To Trump this is the “deep state” corruptly circumventing the will of the people, not good governance. The Trump instinct is authoritarian in nature, if not in practice.

Speak to anyone close to Corbyn, and their concerns in this regard are strikingly similar. Corbyn is not a representative democrat by inclination—his power, like Trump’s, comes from the people that he feels, rightly or wrongly, have been disenfranchised by the system he wants to overhaul. Corbyn and Trump are anti-insiders—and that’s part of the reason they are so loathed in Washington and Westminster, and have such vociferous support in their countries: They cannot be co-opted, because the source of their power comes from without, not within.

The recognition of this informs the collective mind-set of those in Corbyn’s inner circle, according to one senior figure who spoke to me and asked for anonymity. This individual and others close to Corbyn who spoke to me were clear that the grassroots Corbynite campaigning organization, Momentum, is not merely a pressure group to win power. It is meant to act as the Labour leader’s sword and shield once in power, specifically to ensure that the party’s project is not watered down after it is put through the institutionally conservative bureaucratic machine in Westminster. Indeed, according to one recent report, Labour are already thinking about how to stop this from happening, examining ways to force the civil service to deliver manifesto commitments. This should not be a surprise—such thinking has long formed a central tenet of the radical left in the U.K., and was set out by Corbyn’s political hero, Tony Benn, in his 1993 book, Common Sense, calling for a new constitution for Britain.

One incident stands out as the clearest example of Corbyn’s instinctive Trumpism. When The New York Times published an anonymous op-ed from a White House official who revealed how “the resistance” inside was working to keep Trump from making decisions that members felt were dangerous or against the national interest, the reaction among those close to Corbyn was horror—not at the decisions Trump wanted to make, but at the system that was trying to stop him. To Corbyn’s people the report only confirmed the inherently conservative power of the state and the challenges they too would face should they win power.

They are not wrong, either. Imagine the first 100 days of a Corbyn government versus a continued Johnson administration. Which would meet with more resistance for its plans, give more cause for concern to the most established institutions, whether the Foreign Office or secret intelligence services, the Metropolitan Police, or the Scotland and Northern Ireland Offices?

For sure, few, if any, British diplomats or officials I have ever spoken with have been supportive of Brexit, fearing it will weaken Britain’s global influence and undermine the economic model that provides for its Conservative government; these concerns might continue to be held but there’s little prospect that they will have any impact—Johnson has already negotiated what he calls an “oven ready” Brexit deal to take Britain out of the EU, which could be ratified within weeks of the election. This would be game over for British membership of the EU (if not the future relationship which will have to be negotiated thereafter).

But a Corbyn administration, like Trump’s in the U.S., would be deeply problematic for the British establishment, particularly in the area of foreign policy. Corbyn’s open sympathies with Hamas, Hezbollah, the IRA, Iran, Venezuela, and Cuba, and with Russia’s hostility toward NATO, are already proving concerning for Britain’s Five Eyes security partners, just as some have claimed that Trump’s relationship with Vladimir Putin has concerned Western intelligence agencies.

Given that he has not once supported military action—and has been distinctly skeptical of even the need for NATO itself, would Corbyn commit to NATO’s collective defense as has been British policy since the organization’s inception? That’s an open question. Would he commit to using Britain’s nuclear deterrent if attacked by a foreign adversary? He has not in the past and has been a life-long campaigner against nuclear weapons. To not do so, however, effectively disarms a central pillar of Britain’s defense. What would happen to the “special relationship” with the U.S.? Corbyn would, by a distance, be the most anti-American prime minister since World War II. How would the intelligence services and Foreign Office work to protect this alliance during a Corbyn premiership? Those I spoke to said it would look a lot like the efforts of the Pentagon and State Department to protect U.S. alliances in the face of Trump’s controversial moves.

Like Trump, Corbyn has also cast doubt or sought to shift the blame for Russian acts of aggression, whether the attempted assassination of the former double agent Sergei Skripal in Salisbury last year or the invasion of east Ukraine, which the Labour leader said was “not unprovoked.” In the same article, for the Communist daily newspaper The Morning Star, he described the EU and NATO as “tools of US policy in Europe.” Corbyn, like Trump, is also partial to a conspiracy theory. In 2004, he signed a parliamentary motion claiming NATO 1999 intervention in Kosovo to stop the Serbian slaughter of ethnic Albanians was based on “fraudulent justifications for intervening in a ‘genocide’ that never really existed in Kosovo.”

Corbyn’s instincts are revolutionary, Johnson’s are conservative. Corbyn wants to drain the swamp and replace it with a public swimming pool whose entry will be rationed by a Labour government. Johnson is rather comfortable in the swamp, a happy member of the establishment with no intention of getting rid of it. Corbyn believes the traditional media are enemy combatants; Johnson is a former magazine editor and columnist for one of the most conservative newspapers in Britain, the Daily Telegraph, who believes the media knockabout is all a bit of a game. Corbyn wants a social and economic revolution in Britain; Johnson—one of his closest aides has quipped to a journalist friend of mine-—is really offering Blairism, but a bit harder on crime.

Corbyn is prickly and reacts badly to criticism, utterly convinced of his own righteousness—unwilling to bend or bow (a trait that earns him the admiration of his supporters who have grown to loathe “weather vane” politicians). Johnson in contrast, according to those who know him and whom I’ve spoken with, is much more affected by criticism, unsure of his own convictions, even aware that he might not really have many. He is an elitist—and of the kind Trump most detests, intellectually snobby, the type to regard gold-plated toilets and private jets with amusement rather than jealousy.

This takes us to the deepest similarity between Trump and Corbyn, which sets them apart from Johnson.  Trump's and Corbyn's instincts match those of their base. Johnson’s do not.

Corbyn and Trump share wide support among their followers, who are prepared to overlook their flaws and scandals—however serious and contradictory to their stated worldview—because, when all is said and done, they share the same instincts, they feel the same things. In the U.S. this allows the thrice-married, philandering New York billionaire to win the support of rural conservative America. None of those characteristics matter if voters feel he agrees with them: that America is too soft, or being overrun, or losing its identity.

In the U.K., equally, Corbyn’s leadership has seen a previously unimaginable re-awakening of anti-Semitism on the left, in which Jewish members of Parliament have felt bullied out of the party and have accused him of allowing racism to flourish. Yet he has retained the support of the most progressive, “anti-fascist” elements of the left, whose defense of multiculturalism and immigration has seen the Labour Party adopt a policy of guaranteeing the right of European citizens to live and work in Britain even after Brexit. To Corbyn’s supporters, he can’t be the bad man his critics claim he is, because he believes in the same nice things that they do: in world peace and socialism, in ending homelessness and tackling Islamophobia. Myopically, his supporters question how such a man could be racist, ignoring the history of anti-Semitism that exists on the right and left of politics, progressive or otherwise.

Johnson supporters require a different form of cognitive dissonance: to believe your instincts are his, even if the evidence suggests they’re not. For this and all the rest, Johnson isn’t Trump. He loves the establishment and all its pomposity too deeply—he just wants to be the greatest member of it. Corbyn’s your man for getting into a real fight with it.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.