Target, the US discount retailer, on Wednesday removed the gloves in a proxy battle with Bill Ackman, the activist investor, accusing him and his Pershing Square investment group of seeking seats on its board “to advance his own risky agenda”.

In a letter to shareholders, Target’s chief executive, Gregg Steinhafel, urged them to re-elect four board members at Target’s annual meeting in late May. He attacked what he called Mr Ackman’s “hasty and last-minute selection” of his alternative nominees, and defended Target’s decision to reject previous proposals from Mr Ackman on restructuring its real estate portfolio.