The National Trust risks being mired in "years of conflict" if a proposal to ban trail hunting is backed by members today, countryside campaigners have said.

Tim Bonner, the chief executive of the Countryside Alliance, warned that other field sports could face bans like grouse shooting and fishing.

There are already talks about a new campaign among environmentalists to ban grouse shooting on two National Trust moors in Derbyshire.

Baroness Mallalieu, the alliance's president and a member of the National Trust, added that "from being regarded as the custodian of our countryside, the charity is well on the way to being seen as the manager of a bland and sanitised theme park".

As many as 500 members are expected to attend to vote in person at the meeting today in Swindon. The vote was open to the Trust's five million members.

Mr Bonner told The Daily Telegraph: "Any decision to ban trail hunting on National Trust land would launch years of conflict within the Trust as hunting members seek to reassert the right to hunt on land which has been hunted for generations.