WPP said it has built “a two-year shock absorber” into its business model, allowing it to trim staff and other costs should its markets weaken.

Sir Martin Sorrell, chief executive of the world’s second-biggest advertising group, said WPP had seen “little or no impact” from the crises in subprime mortgages and monoline insurers, adding that the 5 per cent revenue growth it had seen in January suggested that “2008 should be a better year than 2007”.