JEREMY Corbyn has vowed to do "everything necessary" to stop a farming "no-deal carnage" amid fears leaving the EU without an agreement could lead to the slaughter of millions of lambs.

The Labour leader made his pledge as fellow opposition leaders responded positively to his call for a strategy meeting at Westminster next Tuesday to find a way to stop Boris Johnson leading Britain towards a no-deal outcome.

British farmers could face an EU tariff of 46 per cent on lamb leading to fears that, if the lamb meat could not be sold, there would be culls of millions of sheep to prevent them dying of starvation.

The UK Government, however, has insisted culling livestock is "absolutely not on the cards".

Speaking ahead of his visit to a farm in Keswick in Cumbria, Mr Corbyn said: "The needless, forced slaughter of millions of sheep is the perfect metaphor for a no-deal Brexit.

"The damage to our farming industry of such a reckless and unnecessary act is symbolic of Boris Johnson's approach to Brexit.

"There is no mandate for this no-deal carnage, which we will do everything necessary to stop," declared the Labour leader.

His Labour colleague Sue Hayman, the Shadow Environment Secretary, warned the UK's food security was at stake, noting how thousands of jobs depended on British farming.

"A no-deal Brexit risks the future of our countryside as well as our nation's food security. Now is the time to fight to save our farms from being undercut and sold down the river by this Conservative government," she said.

However, Theresa Villiers, the Environment Secretary, saying: "We have already been very clear that when we leave the EU on October 31 we will make sure farmers get a better deal and a widespread cull of livestock is absolutely not on the cards.

"When we leave the EU we will maintain the same funding for farm support until the end of this Parliament and we will look to provide additional support where necessary in relation to EU exit. We will make sure that Brexit works for farmers across the whole country."

Meanwhile, leaders of the Liberal Democrats, the SNP, Change UK, Plaid Cymru and the Green Party have all agreed to attend the opposition strategy meeting aimed at stopping a no-deal Brexit.

Jo Swinson, the Lib Dem leader, tweeted: "I look forward to discussing how we can stop the disastrous consequences of no-deal and will be asking Jeremy Corbyn if he is open to all options to prevent it. We have to focus on plans that have a chance of success."

Mr Corbyn has also invited a number of prominent Conservative Remainers to the meeting. However, one, Nick Boles, declined the invitation, saying he could not support the idea of a Corbyn-led government. He urged the party leaders to focus on legislative measures to stop a no-deal Brexit rather than calling a no-confidence vote to cause a general election.