The Takeover Panel's code says that a firm cannot say that it might improve an offer without actually doing so.

BBC: NEWS | Business | Watchdog criticises Standard Life

Last month, opposition peers backed a move to ensure the panel's City Code on mergers and takeovers would provide a "safe harbour" for people accused by the FSA of market abuse.

BBC: Row over finance watchdog shake-up

They argued that both the code and the panel had a proven track record and warned the FSA could be drawn into takeover battles as a delaying tactic by those opposing the bid.

BBC: Row over finance watchdog shake-up