Simon Tisdall looks at the downside of coalitions:
Proportional representation in Britain, by increasing the likelihood that parties such as the BNP would win seats, could one day bring a repeat of the situation in Austria in 2000 when the mainstream conservative People's party formed a ruling coalition with the neo-Nazi Freedom party of the late Jörg Haider. In Italy, too, prime minister Silvio Berlusconi, no blushing liberal he, is sustained in power by those even further to the right.
Coalitions run the world's largest democracies, notably India, Pakistan, Brazil and Japan. In the US, both the Democratic and Republican parties are, in effect, grand coalitions embracing a wide range of groupings across the political spectrum with all the contradictory, internal tension that implies. In Israel, fractious, multiparty coalitions are a constant, and constantly bedevil attempts to advance key aims such as the peace process.