As the Germans try to bring order and transparency to the merger process with their own takeover code, UK lawyers are busy thinking of ways to circumvent their panel rules following the decision to hold advertising giant WPP to its £434m accepted bid for Tempus.

Allen & Overy had been locked in negotiations with the Takeover Panel for weeks, arguing that its client WPP should be allowed to withdraw its bid on the grounds of a material adverse change in circumstances following the 11 September terrorist attacks.