The rules around fox hunting in England and Wales could be controversially relaxed as David Cameron plans to give Conservative MPs a free vote on the issue as early as 16 July.

The prime minister supports a change to the law, which currently means only two dogs can be used to help hunt a fox.

The reform would see a full pack of hounds used to flush out the mammal before it is shot, in a bid to keep the number of foxes under control.

The legislation could be passed under a so-called 'statutory instrument', an executive order of the all-Conservative government that would avoid a lengthy debate and approval process.

But since Tory MPs will have a free vote, rather than a whipped one, they have the opportunity to vote against Cameron's position.

The Spectator reported that Cameron will put the plan to the 1922 Committee today (8 July).

"If the Tories go for it, the statutory instrument could then be debated as early as next week. If passed by MPs, it would go to the Lords for debate in the autumn. If approved there, it would take effect immediately, so the new regime would begin this winter," the right-wing magazine said.

Queen guitarist Brian May, who is also a well-known animal rights campaigner, urged supporters of his Team Fox campaign to write to their MPs about the issue.

"The idea that this device could be used to circumvent the will of the majority of the English people is actually an outrage, and will be viewed by all decent folks as disgraceful conduct by any government, and an abuse of parliamentary procedures," he blogged.

"It's time to write to your MP – not just to say 'vote against repeal of the Hunting Act'– because this vote may now never happen."

The Hunting Act, which was introduced by Tony Blair's New Labour government, came into force in 2005. Cameron, who has ridden in a hunt, promised ahead of the 2015 general election that the Tories would hold a vote on whether to repeal the legislation or not.

"The Hunting Act has done nothing for animal welfare. A Conservative government will give parliament the opportunity to repeal the Hunting Act on a free vote, with a government bill in government time," the PM wrote in the Countryside Alliance magazine.