In a letter to one of the Prime Minister's constituents, Mr Blair's agent, John Burton, said the Government could be prevented from getting its Bills through Parliament if peers decided to filibuster.
"Several Tory lords have expressed to Tony that hunting is the most important thing in their lives, and that they would be prepared to take any action necessary to ensure that they can continue to practise their `sport'. (sic)... This means that the reform of the House of Lords has to take place before any fox-hunting Bill goes before Parliament," he wrote.
Mr Burton told The Independent that Mr Blair remained opposed to hunting, but did not believe a Bill to ban it could succeed this year. "It's fairly obvious if people are going to talk it out we have got to wait," he said.
Mr Burton's letter was sent to The Field magazine by Norman Welch, a pro-hunting constituent of Mr Blair's who had written to him to ask for the Prime Minister's views.
Although most pro-hunting peers are Conservatives, there are a few cross- benchers and Labour supporters among their number. The president of the Countryside Alliance, which has campaigned hard against a ban, is Baroness Mallalieu, a Labour life peer.
Paul Latham, a spokesman for the alliance, said most hereditary peers and even possibly a majority of life peers were in favour of hunting. "They would fight tooth and nail," he said. "I don't know that there has been any official approach to Tony Blair, but I guess this has happened within the corridors of Westminster."
Mike Baker, the director of the International Fund for Animal Welfare, attacked the peers' stance. "This is a classic illustration of how out of touch hereditary peers are with public opinion and the democratic process," he said.
Anti-hunting groups will be looking carefully at the names of MPs who emerge in the top 10 in next month's ballot on private members' Bills to see if any are strong supporters of their cause.
Last year the MP who came top of the ballot was the Labour member for Worcester, Michael Foster, who brought a Bill to ban hunting with dogs. However, his measure was talked out before it even reached the House of Lords, despite passing its second reading in the House of Commons with an overwhelming majority.
Peers Who Back Hunting
Many hereditary peers are active supporters of hunting. They include:
Lord Annaly, who assisted the organisation of this year's Countryside Rally.
Viscount Astor, chairman of the Old Berkshire Hunt.
Duke of Beaufort, master of the Duke of Beaufort's Hunt.
Lord Davies, master of the David Davies Fox Hounds.
Earl Bathurst, ex-master of Earl Bathurst's Foxhounds.
Duke of Buccleuch, who invites the Countryside Alliance to open days.
Earl of Carnarvon, the chairman of the Standing Conference on Country Sports.
Lord Carrington, who proposed a pro-hunt candidate to the National Trust board.
Marquess of Cholmondley, who invited the Mid-Cheshire Minkhounds to meet at his estate.
Lord Denham, author of a book called Foxhunt.
Duke of Devonshire, who backed the countryside march
Marquess of Donegall, chairman of Wexford Foxhounds.
Viscount Downe, chairman of Derwent Foxhounds.
Earl of Kimberley, who lists field sports as an interest in Who's Who.
Viscount Nutsford, who lists field sports as an interest in Dod's Parliamentary Companion.
Lord Mancroft, deputy chairman of the British Field Sports Society.
Viscount Portman, master of the Golden Valley Hunt.
Marquis of Zetland, chairman of the Zetland Foxhounds.
Earl of Romney, who lists foxhunting as a recreation in Dod's.Reuse content