Nick Clegg and his Liberal Democrat ministers are spending their annual conference in Glasgow slapping down red lines for any negotiations over another coalition after the next election.

The deputy prime minister has suggested any deal with the Tories would have to include tax hikes on the rich and no rejection of human rights laws. And he has claimed he won't accept Tory welfare cuts.

Others have suggested there would be no deal with any party that demanded Clegg's head as a condition of coalition while some have urged their leader not to back an in-out referendum on the EU – which he has refused to do.

There have also been some high-octane assaults on the Conservatives. Business secretary Vince Cable claimed George Osborne was "a liar" for suggesting he could balance the books without raising taxes and accused the Tories of wanting to destroy the welfare state.

Treasury secretary Danny Alexander said the Conservatives would "take an axe to your local school" and target the working poor, while former leader Paddy Ashdown said he hated the Tories (and Labour for that matter).

During one of his numerous media appearances, Clegg said: "You've got to remember when I entered into coalition with David Cameron the Conservatives said they cared about the environment, they clearly don't; they wanted to protect civil liberties and human rights – they now want to trash them.

"[They said] that they cared about the more vulnerable in society and yet George Osborne said very clearly last week that their ambition, if they were in government on their own, is to only balance the books by making the working-age poor make additional sacrifices."

But this is all pre-election, party conference sound and fury aimed at reassuring delegate the party still hates the Tories. But no one in Glagow is fooled. Every conference delegate knows their leaders might again seek to join them in government.

And much of the body language in Glasgow has actually suggested the leadership would prefer a second deal with the devil they know, despite the fact the delegates lean far more acutely towards Labour.

Minister Normal Lamb, a close ally of Clegg, went so far as to suggest at a conference fringe meeting that it might be they who demanded a sacrifice if they were to even consider allying with Labour, which appeared unlikley.

"I am afraid I don't see Ed Miliband as a prime minister. And I think the idea of us being latched into a Labour government with a low percentage of the vote, led by Ed Miliband, and what's gone on in France, under Hollande, I think it could be enormously damaging for our party to be in that sort of relationship," he said.

Vince Cable
Vince Cable wants tax rises and more borrowing Reuters

But, leaving aside the fact that previous pledges evaporated when the ministerial cars pulled over and offered them a lift, the bluster at the rally seems to be missing some key points.

First is the fact the party leaders appear casually convinced they will once again be the kingmakers after 7 May. That is far from certain.

If there is another hung parliament it may well be that other smaller parties, including Ukip and nationalists, might have to be factored into any coalition-creating arithmetic.

Next, they appear to be ignoring the growing signs that neither of the two big parties may want to get into bed with them in the first place but might prefer to try to go it alone.

That would very likely lead to a second election within months with the hope voters would give the biggest party a proper majority.

That is a risky strategy and ignores the fact that, once the keys to Downing Street are within their grasp, parties tend to do whatever is necessary to grab them, even if it means dealing with the devil. But for large numbers of Labour and Tory MPs, that would be preferable to doing any deal with the Lib Dems.

Lastly, of course, the Liberal Democrats seem to occasionally believe the electorate voted for a coalition at the last election. They didn't, the result was the inevitable outcome of voters having no enthusiasm for any party - the hung parliament was an accidentasl consequence of disillusion and disengagement.

And, if the other parties want to avoid having to get into bed with the Lib Dems next year, they need to do far more to face up to that problem.