David Prosser: British banks seek a level playing field

Outlook: Mr Darling will have to work hard to prevent British banks becoming disadvantaged

And so the horse-trading begins. The foreign investment banks with a major presence in London have not yet sat down with the Chancellor to discuss whether, like their UK counterparts, they will sign up to his rules on bankers' bonuses – a summit is scheduled for this week – but they are already dropping broad hints that they may not.

What these bankers are saying privately is that they are reluctant to sign up to all the strictures to which the British banks agreed last week. Alistair Darling may yet have to read stories about a bumper round of bonuses next March, just as he tries to put the financial crisis behind him in an election campaign.

Nor do the foreign banks believe they have much to fear from Mr Darling's threat to disqualify the directors of institutions that do not fall into line. It would be difficult to see how the Chancellor's reach could be extended to Goldman Sachs in New York, say, or Deutsche Bank in Frankfurt.

The difficulty with the outcome of the G20 summit in Pittsburgh was always going to be that its agreement on bankers' bonuses would be open to interpretation during the implementation process. Britain and France is complying quickly with the letter and spirit of the agreement. We haven't yet heard much from the US on how and when they will bring in the new rules.

The City has always feared that a regulatory crackdown on UK banks could leave them at a disadvantage to rivals based in jurisdictions where the authorities prove slower to act – or act less thoroughly. Mr Darling will have to work hard this week to prevent such a disadvantage developing in the area of bankers' remuneration.