I must apologise, must I not. I spent any spare moment yesterday glued to the #g20 Twitter stream, which says much in itself, not only about my indolence but about the relevance of PMQs to the concerns of the outside world.

It’s the nature of the beast with the G20, I think. It’s hard enough for journalists and commentators with thousands of words at their disposal to say anything meaningful about such a complex, open-ended and uncertain set of negotiations. A half-hour clutch of stage-managed questions and answers frequently interrupted by partisan honking stands no chance.

But before the G20 came up, Cameron opened on the question of the MPs expenses review and, unusually, made himself look like a bit of a tit by demanding a meeting between the three main party leaders. Twice. The second time after Brown had already agreed to one. Brown enjoyed a rare moment of fun with that. Cameron doesn’t often walk into traps that facile, and it makes one realise how much he relies on Brown’s dreadful slowness in debate.

Still, the principle of the meeting called for by Clegg earlier this  week has now been publicly agreed by the other party leaders. Clegg’s quick draw press release on the subject said:

I am delighted that Gordon Brown and David Cameron have taken up my initiative from earlier this week for an urgent meeting to reform the system of MPs’ expenses.

Clegg’s questions, meanwhile, were another attempt to ground the G20 in the practical realities of action needed at home. How was Brown in a position to give lessons to leaders of other countries when his “fiscal stimulus” hadn’t created a single job or built a single house. Brown’s talk sounds good, but when was he actually going to start taking some of the action?

Hansard:

Mr. Nick Clegg (Sheffield, Hallam) (LD): We all want this G20 summit to succeed. The Prime Minister is right to say that we will not get out of this mess unless world leaders work together. However, the summit will not help anybody here unless he practises at home what he preaches abroad. On his world tour, he railed against tax avoidance, yet he presided over industrial-scale tax avoidance in British banks and British businesses. He now talks about green-collar jobs, yet his fiscal stimulus has less green stimulus than any other fiscal stimulus in the G20. Does he not see that leadership starts at home?

The Prime Minister: Let me tell the leader of the Liberal party that for the first time we are on the verge of an agreement, which means that every country that was previously a tax haven will have to exchange tax information on request. So with Switzerland, Andorra, Luxembourg, Hong Kong, Singapore—all the countries with which we have been trying to get agreement for 20 years; I do not know whether the Conservative party wants those agreements, but we have been trying to get them for 20 years—we will get agreements at this summit. The issue of tax havens has moved to a new level, where we are dealing with the problem.

On a green stimulus, I hope that the right hon. Gentleman finds that the communiqué reflects the desire in all countries of the world that we do not return to business as usual on the environment, that the recovery is low carbon, and that we will do whatever we can, now and in the Budget, to move that forward.

Mr. Clegg: The words sound good—they always do—but now the Prime Minister has to do what he says. He is the only G20 leader who has blown billions of pounds of borrowed money on a wasteful VAT cut that has not created a single job. Why should any other leader listen to his lessons? Is it not time for him to admit his mistake, announce at the summit tomorrow that he will  stop the wasteful VAT cut, and invest the billions of pounds in creating the jobs and homes that this country desperately needs now?

The Prime Minister: On the environment, we are the first Government in the world to sign climate change legislation that will commit us to statutory cuts in carbon over the next few years. I know that the right hon. Gentleman’s party does not seem to think it important, but we are leading the world, as we should, in the environmental debate.

On VAT and other changes, I have to tell the right hon. Gentleman that one has to use all the weapons at one’s disposal to deal with a global financial crisis. We have cut interest rates, the Bank of England is now putting money into the economy, we have advanced public works in the economy, and we have raised the pension and child benefit beyond the level that was expected in January. At the same time, we are giving income tax cuts, starting this week, by raising personal allowances. We are also helping the unemployed and home owners who find themselves in difficulty. That is the way to deal with the downturn: to take all measures necessary to get through it as quickly as possible.

Note the sleight of hand reference to raising personal tax allowances as if it’s a “measure”.  The personal tax allowance goes up at the beginning of every financial year. What he means by implying that the Liberal Democrats don’t consider the environment important is, frankly, anybody’s guess, but it’s  fairly representative of the groundless smears Brown often seems to trot out in his second answer, when he knows Clegg cannot reply.

Anyway, as a ticking off, all this is undoubtedly merited. The Prime Minister continues to take an embarrassing amount of pride in his self-appointed role as global saviour, and when his grandiose vision does occasionally alight on Britain, continues to hurl out the odd initiative as a substitute for getting anything done. And Clegg’s narratives dovetails quite neatly with Cameron’s here as well, the latter having referred back to Mervyn King’s doubts about the viability of another fiscal stimulus last week. Both are seeking to point out the contrast between Brown’s own perception of his status abroad and his actual status at home.

But whether even such a common sense grounding has any wider impact, it’s hard to say. Certainly no-one looking for a common sense grounding in economic realities is going to be watching PMQs.

Still, however unproductive and archaic PMQs is as an institution, and however ill-equipped to grapple with complex problems, it was at least the setting for an agreement on the desirability of a leaders’ meeting on expenses yesterday. Clegg originally mooted the possibility on Five Live last week. He won’t be credited of course, but when are we credited? A victory for common sense, perhaps, more than for Clegg.

Watch the session here.