Labour has called on the SNP to vote against plans to amend the law on fox hunting in England and Wales.

Ministers have put forward changes to the Hunting Act to bring England and Wales in line with Scotland on using dogs to flush out foxes to be shot.

Labour will oppose the changes in the Commons on Wednesday while the Conservative ranks have been given a free vote, but the actions of the 56 SNP MPs could prove crucial to the outcome.

In a letter to the SNP's Westminster leader Angus Robertson, Labour frontbenchers Ian Murray and Maria Eagle called for SNP support.

Shadow Scottish secretary Mr Murray and shadow environment secretary Ms Eagle said: "Many people, including in Scotland, will oppose any move by the Government to water down the existing law in England.

"We are sure you, and members of the SNP group, will have already received representations from constituents and others in this regard. It is important that all of us listen to people across Scotland who have been making their views clear since this vote was announced last week.

"The Labour Party will oppose the changes being put forward by the Government. We know that people across Scotland will want to see strong opposition against the re-introduction of hunting with dogs by the back door. Our resolve against these immoral practices should not stop at the border."

SNP MPs do not usually vote in issues which do not affect Scotland, but a spokesman said the party would examine the details of the Government's proposals before deciding what to do.

An SNP spokesman said: "As with all proposals from the UK Government, SNP MPs will decide our position once we have assessed the detail of what is being proposed."

Traditional fox hunting with dogs is illegal across Britain, but in England and Wales, only two dogs can be used to flush out a fox so that a farmer or landowner can shoot it, while in Scotland an unlimited number of dogs can be used.

The bid to change the law in England and Wales has prompted accusations that the Government is resorting to "desperate measures" to sneak fox hunting in through the back door.

Former environment secretary Owen Paterson, who supports a change in the law, clashed with animal rights activist and Queen guitarist Brian May over the issue on Sky News' Murnaghan programme.

Mr Paterson said the proposals were for a "minor technical amendment" which would help farmers who were losing livestock to foxes.

But May told him: "This is nothing to do with farming and I know a lot of farmers now and I can tell you, they don't go around digging out foxes in their spare time to shoot them.

"This is about... people rushing around the countryside torturing wild animals to death for fun, that's what this is about and it is an absolute scam to pretend that this is about farming in the first place."

He added: "This is an excuse, Mr Paterson, to go out there and be fox hunters again. It is a criminal act, you are talking about a criminal act of cruelty."

Mr Paterson said: "So much emotion comes into this issue and I do understand people like Brian have very, very strong feelings but what I find sad is that people don't come to the countryside and talk to farmers and the people I talked to yesterday who have lifelong experience of trying to manage livestock in pretty wild terrain, blocks of spruce 2,000 acres in size, where the only practical method is to use this age-old method which is to flush (foxes) out to guns and that has been proven to work.

"There are other alternatives which are getting worse and I wish people would take the emotion out of this. The ban continues, 95% of prosecutions under the current law will continue.

"This is purely a technical measure helping better management in the hills, enabling our very hard-working sheep farmers to be on the same footing as their compatriots in Scotland."