Backers include the film producer and fisherman David Puttnam, the Royal Opera House director Jeremy Isaacs, Sam McCluskie, the ex-seamen's union boss - a hare courser - and the Mortimers, John (barrister and author) and Penny, who fishes, shoots and rides with three hunts. They want Labour to drop its manifesto commitment to let Parliament decide whether to ban fox hunting, deer hunting and hare coursing.
'Some will try to dismiss us but I think we've got a very impressive list of names,' said Mrs Mortimer, secretary of the Leave Country Sports Alone campaign. Other supporters include two Labour frontbench spokesmen in the Lords: Baroness Mallalieu, a hunting and fishing barrister who covers home and legal affairs, and Lord Donoughue, top adviser to Lord Callaghan when he was prime minister and now spokesman on national heritage.
But yesterday Tony Banks, Labour's most outspoken anti-blood sports campaigner, demanded the sacking of Baroness Mallalieu and Lord Donoughue. 'It's disloyalty,' he said. 'They are seeking to make Labour change policy which it has overwhelmingly supported; they can't do that from the front bench.' He said he and other MPs would be writing to John Smith demanding their dismissal.
No Labour MPs had supported the new campaign because party members and the electorate opposed hunting, said Mr Banks. He accused the campaigners of trying to mislead the public into believing Labour was also opposed to fishing and shooting.
But Mrs Mortimer said Labour MPs had become 'urbanised'. 'There are a lot of Labour supporters who are very opposed to the line the party takes on hunting.'
The Leave Country Sports Alone campaign opens with letters in the Guardian and the New Statesman. Other backers include Lord Shackleton, Sir Denis Forman, the former Granada Television chairman, and Richard Course, a Labour councillor who once headed the League Against Cruel Sports.
The campaign says Labour MPs and councillors have been misled by animal rights propaganda. They are worried that many Labour county councils have moved to ban hunting on council-owned land.