Zurich has until August 25 to make a bid 

Stephen Hester (large)

RSA chief executive Stephen Hester has told Zurich to ‘put up or shut up’ as the Swiss insurer circles for a potential bid.

Hester said: “They have put themselves in a ‘put up or shut up’ situation… the ball is now in their court.”

Under UK rules Zurich has until August 25 to make a bid. 

Zurich has drafted in Morgan Stanley to help plot the bid. A deal for 525p-a-share cash is possible - lower than the 600p mooted by analysts but above the RSA share price of 510p.