David Prosser: Osborne suffers as WPP plays hard to get

Outlook Sir Martin Sorrell made an impact when announcing in 2008 that WPP was relocating to Ireland for tax reasons – and a big splash again in the summer when he said George Osborne's Budget was tempting the company to come back. Since then, nothing.

Until yesterday that is, when Sir Martin told City AM newspaper that the Chancellor had not yet, after all, done quite enough to persuade WPP's executives to pack their bags.

If WPP decides in the end not toreturn, the Chancellor will be embarrassed. He made much of WPP's departure when in opposition – and much of its endorsement of his last Budget. Such is the danger of designing tax policy so specifically with threats or promises from big business in mind.