David Cameron has warned that Britain faces political and economic "stagnation" if the General Election returns a hung parliament.

The Tory party leader's comments came as Nick Clegg claimed the era of the old two-party "stitch-up" was over for good.

With the Liberal Democrats breathing down the necks of the Tories in the opinion polls, Mr Cameron said only an outright Conservative victory on May 6 could deliver a strong government capable of taking the necessary decisions on the economy.

In his starkest warning yet of the dangers of voting Lib Dem, he said the rest of the world would not understand how Britain could tackle its record deficit unless the election produced a decisive result.

He said: "Any other outcome, any other vote, could lead to a sort of stagnation, to a sort of haggling and a bickering amongst politicians and we won't get done what so badly needs to be done in our country.

"If we end up with a hung parliament, the world is going to look at us and say: 'How are you going to sort out your problems?' We need decisive action to sort out those problems and that is what a Conservative government would bring."