Two of Britain's most prominent fox hunting chiefs have issued a call to arms for all their supporters to canvas on behalf of Conservative election candidates backing their campaign to overturn a ban on the blood sport, as two more Tories are revealed to be receiving direct backing.

The plea made by Lord Mancroft, a hunting partner of Prince Charles who chairs the Council of Hunting Association, together with Hunting Office director Tim Easby, will increase concerns among animal rights campaigners that the bar enforced a decade ago could be lifted if the Tories are able to form a government after the general election.

“As the campaign begins in earnest, we are writing to remind you of the vital importance of the result of the forthcoming General Election. The 7th May could be a great date for Hunting,” the pair wrote in an email appeal.

It was sent to hunt members across the country – who now number 45,000 according to the Countryside Alliance but are able to influence many more, with hundreds of thousands of people still thought to attend the biggest events in the hunting calendar – including David Cameron’s local Heythrop Hunt in Chipping Norton, Oxfordshire.

“Whichever way the Election goes, the status quo will change. ‘We are happy as we are’ is not an option,” added Lord Mancroft and Mr Easby. “For those who think we can carry on as we are with the current status quo, consider this. Under a Conservative administration, the current status quo will be the floor, the base level from which things might improve. Under a Labour administration, the current status quo will be the ceiling, from which we dangle precariously from our fingertips.”

The Prime Minister promised last month to hold a parliamentary vote on repealing the 2005 Hunting Act if the Tories win the election. Labour, which introduced The Hunting Act in 2005, is firmly committed to upholding it.

There are an estimated 45,000 hunt members (Getty Images)

The Independent can reveal two further Conservatives – Cheltenham parliamentary candidate Alex Chalk, and Oxford and Abingdon West incumbent Nicola Blackwood – are receiving support from the pro-hunting Vote-OK group run by Otis Ferry, son of Roxy Music frontman Bryan Ferry. This newspaper disclosed last week that David Nuttall, fighting to retain his seat in Bury North, and Rob Loughenbury, standing in Chorley, have been helped by Vote-OK members leafleting, putting up posters and telephone canvassing.

Arguing that every member should take part in such activities, the email said: “Basic campaigning is the most significant and decisive weapon in a candidate’s armoury – potentially making the difference between a minority Government and a Conservative Government with a working majority great enough to win the vote when they bring in legislation to Repeal the Hunting Act. The result is going to be tight, and the tighter it becomes the more valuable your work becomes.”

They warn: “There are some gaps where Hunts are underperforming [in their election support] and we will be contacting these Hunts accordingly.”

Maria Eagle, Labour’s Shadow Environment Secretary, said: “The Conservative Party only stands up for a privileged few and it smacks of desperation that it has to rely on the pro-hunting lobby... to get its message across.”

Tom Quinn, Campaigns Director for League Against Cruel Sports said: “It would be completely wrong to repeal the Hunting Act. Chasing foxes and other wild mammals with dogs for pleasure has no place in modern Britain. That is why 80 per cent of the public support the ban on fox hunting and even more back the ban on stag hunting and hare coursing.

“With the majority of Conservative party supporters against fox hunting, along with those of every major political party in Britain, a growing number of Conservative MPs and parliamentary candidates also recognise that overturning the hunting ban would be the wrong thing to do.”

Lord Mancroft, a Conservative peer who chairs the Countryside Alliance, is probably best known outside hunting circles for claiming in 2008 that the NHS nurses who had treated him at the Royal United Hospital in Bath were “slipshod, lazy and, worst of all, drunken and promiscuous”.

Mr Easby is director of the Maters of Foxhounds Association, representing 186 packs of foxhounds, as well as heading the Hunting Office, which administers all the representative organisations for hunting with hounds in the UK.

Though illegal fox hunting continues in some parts of the country, Mr Easby said the “status quo” referred to in the email meant activities allowed “within the bounds of the Hunt Act”, such as “trail” hunting where a pack of hounds follow an artificially-laid fox scent.

The extent of illegal fox hunting is unclear. Anti-hunt campaigners claim that it is widespread with members routinely ignoring the law, often under the cover of trail hunts. There were only 13 convictions of registered hunts between 2005 and 2013, although opponents say this is because it is poorly policed.