Last weekend, the longtime BBC anchorman Jeremy Paxman called it a “scandal” that English and Welsh voters have no say in Thursday’s Scottish independence referendum. “The fate of this supposed relationship of equals is to be determined solely by those who find themselves living on one side of a border that we have been told for generations no longer really matters,” he wrote. His argument reflected a larger reality: The consequences of a vote for secession would extend well beyond Scotland.

Scotland has been part of the United Kingdom since the Act of Union in 1707. But the U.K., which currently consists of England, Northern Ireland, Scotland, and Wales, is not a country in the traditional sense but rather a political union—or, as John Oliver put it, “an archipelagic supergroup comprised of four variously willing members.”

“Variously willing” accurately sums up Scotland’s begrudging tolerance of English rule over the past 300 years. During that period, a handful of British parliaments have attempted to salve Scottish frustration with the union by devolving degrees of power to Scotland—a cabinet secretary in the late 1800s, a (failed) referendum for a Scottish deliberative body in the 1970s, and a vote for devolution in 1997 creating an independent parliament that would legislate on Scotland-specific issues. Wales and Northern Ireland passed similar referendums that resulted in additional regional legislative assemblies. By 2000, all of the nations in the United Kingdom, except England, had control over certain fields of national policy.

Devolution partially addressed demands for self-government in various parts of the U.K. But it introduced another political conundrum: the West Lothian question, named after a lawmaker from the Scottish constituency of West Lothian who first raised the question in 1977. Simply put, this is the dilemma that Scottish, Northern Irish, and Welsh members of parliament (MPs) in the U.K. Parliament (based in Westminster, the London landmark known for Big Ben) can vote on policies that affect England alone, but the reverse does not hold true for English MPs.

The West Lothian question may seem like a fairly esoteric concept, discussed primarily by scholars of British politics and the occasional disgruntled Conservative politician, angry at Scottish Labour MPs’ power to vote on expanding English welfare provisions. But the question manifests itself in very real ways. When the Scottish Parliament was formed in the late 1990s, certain areas of legislation (such as foreign policy, defense, broadcasting, and immigration) were reserved for the U.K. Parliament. Other matters, like education, agriculture, housing, and tourism, fell within Scotland’s legislative authority. So in Edinburgh, members of the Scottish Parliament vote on education policy within Scotland; in London, Scottish members of the Westminster Parliament vote on education policy within England. Nowhere do English MPs vote on Scottish education policy—which makes perfect sense, in theory, but in practice produces an imbalance in legislative authority.

Devolution, in other words, means there is no place where English lawmakers can vote on their own bills without the influence of MPs from neighboring nations. And given partisan disparities between England and Scotland, this influence can be quite strong. Scots’ political leanings are generally further to the left than those of their English counterparts. In the 2010 election, which brought Conservative Prime Minister David Cameron to power, the Labour Party won 41 of the 59 Westminster constituencies in Scotland while the Conservative Party won just one. (Conservatives, by contrast, won more than half of the 533 parliamentary seats in England.) The impact of these more liberal Scottish MPs has been evident several times since devolution, once in approving higher tuition fees for English universities—a measure that notably did not apply to Scottish schools such as St. Andrews and the University of Edinburgh.

A ‘yes’ vote on Scottish independence would have major consequences for the West Lothian question (especially since Northern Irish MPs come from regional Irish parties, and Wales is split more evenly between the U.K.’s main two parties, though it leans Labour). It would also eliminate a Labour stronghold in Westminster, making the partisan makeup of those who vote on England-only legislation somewhat more aligned with English political leanings.

But the resolution of the question largely depends on how the referendum shakes out. And the run-up to the poll has only added new urgency to the debate. In the event that Scotland votes 'no' on Thursday, some Conservative Party leaders are urging Westminster to revoke the right of Scottish MPs to vote on English-only legislation. Others are calling for more dramatic constitutional overhauls of the United Kingdom. “While the majority of us would like Scotland to stay in the UK, a large majority of us in England now want devolution for our country too,” John Redwood, a Conservative MP from southeast England, wrote in the Financial Times on Wednesday, on the eve of the independence vote. This devolution, he argued, could take the form of an English Parliament as well.

“What has emerged from the Scottish referendum is the idea of a federal state, with much greater power being exercised in the constituent nations of the union,” he noted. “What is fair for Scotland now also has to be fair for England.”