David Prosser: Bankers' bonuses are a slam dunk for a Treasury in need of cash

Outlook So what took them so long? The Liberal Democrat conference was going on for at least 24 hours before Vince Cable began sounding off about bankers' bonuses. And his boss, Nick Clegg, was even slower off the mark.

Still, let's see what George Osborne has to say about bankers' bonuses when the Chancellor addresses the Conservative Party conference in a couple of weeks' time. As the only Coalition Government minister with the power to crack down on bonuses, via some sort of tax charge, he's much more worth listening to than Messrs Clegg and Cable, even if they must have relished to chance to throw their party a bone.

Will the Chancellor talk so tough? It seems less in the character of Mr Osborne to do so and he will surely know that the evidence is that there is just no way to prevent the banks paying bonuses of a size likely to prompt anger. The payments may be structured differently these days, with most bonuses paid in shares, and often locked up for an extended period, but they will still be made.

Last year, Alistair Darling said his tax on bonuses would raise a few hundred million pounds and that the charge was less intended to be a revenue-raising measure and more an attempt to rein in the banks. In that regard, it was a complete failure, though the happy compensation for the policy's uselessness was a windfall to the Treasury of around £2bn. If Mr Osborne has any sense, he will follow suit and hope for a similar boost. There is not an iota of political risk in targeting the banks and not much risk to the competitiveness of the City either, judging by last year's experience.

Both domestic and international banks carped about Mr Darling's levy on their bonus pools, but paid up nonetheless. No one seems to have left town in a huff. All that said, bonuses may in any case be less of an issue over the months ahead than might be expected.

While banking profits are buoyant this year, it has been the retail operations that have been performing most strongly. By contrast, banks' investment banking divisions, the really big bonus payers, are having a much less impressive year and there is good reason to think total remuneration will be down on 2009.