Top retailers have written to London mayor Boris Johnson urging a more energetic response to the recession.

Selfridges, Harrods, Fortnum & Mason, John Lewis Partnership, Marks & Spencer and shopping centre group Westfield were among 19 businesses that signed a letter sent by business organisation London First.

They want the mayor to spend more on marketing the capital to foreign tourists, “seizing the opportunity afforded by a competitive exchange rate” to boost spending and consumer confidence.

The businesses also want a promotional campaign for London that “engenders a wow factor, to create a new buzz”.

Johnson responded that he does not want to spend taxpayers' money “prematurely” and said: “We want to wait and decide when is the moment of optimum impact.”