Britain faces a disruptive second election before Christmas if either of the two main parties try to govern alone as minority governments after Thursday's (7 May) ballot, Nick Clegg, the deputy prime minister and Liberal Democrat leader, warned on Tuesday (5 May).

Two days before the country's closest election since the 1970s, Prime Minister David Cameron's Conservatives and the opposition Labour Party are level in most polls with neither on track to win outright.

That raises the prospect of another coalition, something Britain has had since 2010, or of one of the two main parties trying to govern as a minority administration relying on smaller parties for support on a vote-by-vote basis.

Clegg, whose centrist party has been in coalition with Cameron's Conservatives for the last five years, wants to form another coalition with whoever wins the most seats and votes in Thursday's election. He therefore has an interest in talking up the risks of minority governments.

He said a minority government would turn into "a shambles" because it would be vulnerable to the whims of smaller parties such as the Scottish National Party and the anti-EU UK Independence Party who would demand "sweeteners" in return for their short-term support.

''They want to create a messy, unstable government, on the one hand, in the hands of Nigel Farage and the right wing, imposing ideological cuts, cuts, cuts, way beyond what is necessary. Or, on the other hand, in the hands of Alex Salmond, borrowing pots and pots of money that we don't have, all that hard work, all those sacrifices made by millions of our fellow citizens as we had to go through this difficult time over the last few years, will all have been wasted. The last thing that Britain needs is a second election before Christmas,'' he said.

Prime Minister Cameron is spending the last push of the campaign touring the west of Britain, from Cornwall to the north-west in an attempt to win 23 marginal seats, which he believes if he wins, would be enough to create a majority government in parliament.

Labour's Miliband spent Tuesday campaigning in the midlands, posing for selfies with party supporters, after a poll by Lord Ashcroft published on Tuesday, showed that the Labour party trail the Conservatives by two points.

Despite Clegg and Cameron's comments, the Labour leader had previously ruled out working with the Nicola Sturgeon and the Scottish National Party (SNP), who could hold the key to who will lead the next British government.