Actress Imogen Stubbs will be part of the panel

Giles Foden, author of The Last King of Scotland, will join poet Wendy Cope, biographer and critic Ruth Scurr and actress Imogen Stubbs.

The chair of judges is Howard Davies, director of the London School of Economics and Political Science.

The 2007 longlist will be announced in August, followed by the shortlist in September, with the winner named at a ceremony in London on 16 October.

For the first time, the longlist will be confined to a "Man Booker Dozen". In previous years, there have been as many as 22 books on the list.

The judges will have to be a bit tougher on themselves Ion Trewin Prize administrator

Prize administrator Ion Trewin said: "In the past there has been rather a vagueness about the numbers.

"We thought it would mean something more if the longlist is reduced and also be easier to cope with. It means that the judges will have to be a bit tougher on themselves.

"It will also give people the chance to test their own judgement against that of the panel because 12 or thereabouts is a reasonable enough number to read."