Speaking to Tory backbenchers recently, several have raised the idea that they and the Liberal Democrats should come up with a new coalition agreement.

Their thinking is that much of the old one has been undertaken. Many of the points consisted of quick absolutes like abolishing things, or open-ended notions where the coalition would 'work towards' this or that.

Apart from that there are the big areas government wanted to address; in particular the deficit, an ongoing process for which the plan has been set out.

Then there is NHS reform, which is moving towards the implementation phase, as is Iain Duncan Smith's welfare reform. The defence review, through which the MoD's budget has been balanced, moves ever onwards and we know where the government is headed on policing, immigration and political reform.

And yet we still have three years to go until the next general election. The question for coalition strategists is what do they want those three years to be filled with?

If they are not careful it will be two things; endless reports about fewer police, nurses and soldiers as the cuts bite ever deeper and, secondly, endless squabbling between coalition MPs, making an already rebellious Parliament intolerable.

Meanwhile the kind of political 'differentiation' currently being practiced by the Conservative front bench cannot go on for three years; there is no substance to it and it simply does not make for good government.

Without a more substantial direction for the coalition, the government risks simply being carried along by events, constantly reacting to news rather than setting the agenda.

The coalition needs something, say these MPs, which will redefine its purpose for the second half of its term, with growth in the economy the theme running throughout any new agreement.

It should be something which would refocus MPs and, importantly, tell them where the lines are; what each party is going to get from here on in and what they are not going to get before 2015.

That would give everyone something to talk about, but also allow each party to define themselves by being clear in saying 'this is what we can do now, this is what we would want to do if we got our own majority'.

The Queen's speech was a missed opportunity to do just that, say the members, and the budget, an absolute disaster. The coalition needs fuel in its tank if it's going to get to the end of the line.