LONDON (Reuters) – Cadbury fired the final salvo in its defence yesterday, branding Kraft Foods' bid as more unattractive than a month ago, as Cadbury shares rose on hopes of a rival bid from Hershey.

But as Cadbury's Chairman Roger Carr attacked Kraft's bid and its past performance, analysts remained doubtful over how the much-smaller Hershey could finance an offer for Cadbury and top Kraft's £10.5 billion ($17.1 billion) hostile bid.

"Kraft's offer is even more unattractive today than it was when Kraft made its formal offer in December," Carr said in a final defence leaving Kraft five days to sweeten its offer.

Because the bid is over half in Kraft's shares, it exposed shareholders to Kraft's history of missed targets compared with Cadbury's robust results and excellent momentum into 2010, while the deal undervalued Cadbury compared with recent deals, he added.

This came after Britain's Business Secretary Peter Mandelson met with fund managers to urge them to take a more long-term view in takeover bids, and as Kraft's CEO Irene Rosenfeld went from door to door to woo Cadbury shareholders in London. Hershey is still working on a Cadbury bid to top Kraft's offer according to a source familiar with the matter on Wednesday, while the Financial Times said Hershey had authorised drawing up a bid for Cadbury and making an offer within weeks.

But analysts said a solo Hershey bid could be extremely challenging as Hershey is only half the size of Cadbury and a big share issue would dilute the controlling Hershey Trust, while Kraft still has the option to sweeten its current bid.