Liberal Democrat leader Nick Clegg sought to kill talk of a post-election deal with the Tories on the final day of his spring conference in Birmingham amid signs it would provoke an angry backlash from his party.

As expectations of a hung parliament grew, the Lib Dems’ final conference before the general election expected on May 6 was dominated by speculation about a coalition government.

Delegates in Birmingham have made clear, however, their strong animosity towards the Conservative Party.

Lib Dem MPs warned privately that a majority of the parliamentary party would not support Mr Clegg if he entered a formal coalition with the Tories.

Aides to the leader indicated he would not attempt to do anything that did not carry the party.

In his keynote speech at the close of the three-day gathering this afternoon, Mr Clegg rowed back from any impression that he was courting either the Tories or Labour.

“I am not the kingmaker,” he insisted. “The 45 million voters of Britain are the kingmakers.

“They give politicians their marching orders, not the other way round.”

Insisting that the Lib Dems were not a “wasted” vote, he suggested that the party was in fact a small step from emerging as the dominant force in the House of Commons.

“Almost one in four voters chose the Liberal Democrats at the last election. If that increased to one in three, we could lead the next government,” he insisted.

“This election is a time for voters to choose, not a time for politicians to play footsie with each other.

“The party which gets the strongest mandate from the voters will have the moral authority to be the first to seek to govern.”

He pointed to the fact that 32% of people did not vote for Labour or the Tories at the last general election as evidence that the two-party system was giving way.

However, two new polls show that Mr Clegg is well short of winning a third of the popular vote.

According to ICM they were on 21%, and according to YouGov just 17%.

The polls also indicated that the Tories’ lead over Labour - at, respectively, four points and seven points - was not enough to guarantee Mr Cameron a clear Commons majority.

But MPs from the “progressive” wing of the Lib Dems claim privately that there would be very little support for a formal coalition with the Tories.

Any deal at all - for example an informal arrangement on an issue by issue basis - would have to ensure that the Lib Dems’ independence was not put at risk.

Leading Lib Dem supporter Claire Rayner urged Mr Clegg against cosying up to the Tories.

Mrs Rayner, a member of the party’s powerful federal policy committee, told the Mail on Sunday she felt “queasy” about the leader’s apparent praise for Baroness Thatcher in recent interviews.

And she added: “If you start hinting now that you’re ready to sign up to a cosy deal with the Tories, you might as well shut up shop and be another Conservative Party and be done with it.”

Mr Clegg was also pulled up by a delegate on the conference floor on Saturday about what she felt was his warmness towards Thatcherism.

He insisted he had opposed “pretty well” everything Lady Thatcher had done as prime minister.

Amid questions yesterday (Sunday) about the prospect of internal Lib Dem wrangling about how they would move forward in the event of a hung parliament, his spokeswoman said no leader “worth their salt” would attempt to do something their party would not support.

Mr Clegg also stepped up his criticism of the Tories after making plain yesterday he would not support their plans for immediate cuts which would put the recovery at risk.

That opens the prospect of a minority Conservative administration being incapable of even getting through their first emergency budget, which they have promised to hold within 50 days of forming an administration.

In his speech, he accused the Tories of leading a “protection racket” as they try to frighten voters into electing a Conservative government.

Their warnings about the threat to the markets of a hung parliament demonstrated their desperation that victory at the general election was slipping from their grasp, he said.

Tory leader David Cameron, shadow chancellor George Osborne and shadow business secretary Ken Clarke have suggested there could be a sterling crisis if they do not win a clear mandate for swift action to cut the deficit.

Mr Clegg said: “David Cameron, George Osborne and Ken Clarke marched into the City of London the other day and declared that if voters didn’t give them the result they want, the markets would tear the house down.

“Cynical, desperate, the Tories think they’re entitled to victory - the moment they feel it slipping from their grasp, they start lashing out.

“It’s a political version of the protection racket - do what we want, or else.”

Mr Clegg struggled with his voice and sipped water throughout the speech, having been under the weather all weekend. He was drinking hot lemon and honey beforehand.

The conference is thought to have brought an estimated £11 million boost to the West Midlands.