The leaders of both coalition parties are seeing ministerial colleagues and backbenchers trying to push them further way from the centre at present. Nick Clegg has Vince Cable continuing to push for what Ed Miliband might call ‘good borrowing’, telling the Today programme that he’d borrow to improve the economy, rather than to keep an inefficient economic model going. He said:

‘There’s borrowing for different reasons, and this was the point I was trying to make last week, that you can borrow simply to plug the hole in the deficit… The metaphor I’ve used which helps to explain it – there’s a difference between increasing your credit card in order to keep a gas-guzzling car on the road, and taking out a loan in order to get a more fuel-efficient car, and the latter is a more sensible form of borrowing. And that’s what, when people talk about capital investment, that’s what we mean. And those companies would make that distinction, and that’s a sort of healthy form of borrowing, providing you get good projects.’

Liam Fox, meanwhile, seems very excited about the speech he is giving this morning to the Institute of Economic Affairs, tweeting a photo of himself doing the final run-through. Funnily enough, he’s making similar attacks on the concept of ringfencing as Cable, although some of his other ideas might be closer to what the Business Secretary dubbed ‘some kind of ideological jihad against public spending and public services’.This is not Fox’s first intervention on the economy, and it won’t be his last, either. But it is a significant piece of positioning from a man who has worked extremely hard on relations with other MPs on the right of the party.

By speaking before the Budget means that if Osborne delivers a statement that sets hares of disagreement and U-turn running around Westminster rather than a rabbit that keeps everyone happy, Fox can become a rallying figure for discontented Tory MPs. Remember the Budget is the next in the five key tests set by backbenchers – and the government has already failed the first two.

Those sitting in the Chamber will see the first signs of whether the Budget has worked as backbenchers watch the Chancellor deliver it. Last year there were certain announcements – the ‘granny tax’ being one of them – that MPs immediately spotted as being troublesome, and they started leaning towards one another to mutter about it. Too much of that quiet backbench muttering will suggest the Chancellor hasn’t kept things as steady as he’d hoped. All that those who don’t dream of an exciting coup this side of 2015 want is a ‘steady as she goes’ Budget with some gestures on the cost of living.

But the difference between these two groupings on either side of the leadership is that Clegg, as James explained in his Mail on Sunday column, is feeling secure against an attack from Vince. The Lib Dem conference this weekend showed that the biggest source of discontent comes from party activists, and the Liberal Democrats are becoming more like a party in government as they are starting to worry less about the long-term consequences of revolts from their members. But Cameron cannot feel quite so secure, given the febrile mood in his parliamentary party, and the number of senior figures setting themselves up as potential rallying points for when things get really rough.

Tags: Budget, Economy, Liam Fox, UK politics, Vince Cable