Ministers are entering a "critical era" in its relations with business, the CBI president will tell Gordon Brown tonight.

John Sunderland give his blunt message to the chancellor as both men attend the CBI's annual dinner.

Sunderland will warn Brown that the corporate sector has run out of patience with higher taxes.

He will say: "You have assured us that you have no intention of adding further to the significant taxation burdens which have already been imposed on business over the last eight years . . . Be certain that we will hold you to that.

"British business has never been more challenged by global competition - and never been freer to move abroad if the challenge becomes too strong."

Gordon Brown will use his speech to reject the EU push to impose a shorter working week on Britain and will attack the economic management of the Union.