Cadbury has approached the UK Takeover Panel to ask Kraft to “put up or shut up” on the unsolicited £10.2bn takeover approach from the US food group unveiled three weeks ago.

Cadbury approached the panel on Monday to ask Kraft either to make a formal takeover proposal or walk away for six months, said people close to the matter, after Kraft made an indicative offer in late August that was initially valued at 745p a Cadbury share.