Esther McVey tore into Labour for their farming tax on the BBC this morning, accusing Rachel Reeves of basing it on “miscalculations”.

The former cabinet minister left a Labour MP reeling as she warned him not to try “justifying your mistakes”.

She blasted: “You didn’t do the research on it, it was based on miscalculations!”

“Even a Labour tax advisor, Dan Neidle, now having looked at the figures has reversed what he said and actually you’re doing it wrong you’re going to hurt farmers.

“Farming families, and actually what you wanted to do is try and get those wealthy people who invest in land, you should have gone in by a different way this is all about ideology with no research and the implementation is going to be shocking.

“That is truth. Now I’m hoping you’re going to back peddle I’m hoping you’re going to increase the amount but please don’t try and justify your mistakes and dig in deeper.

“Why do you think we’re having protests on the streets, you have made a big big mistake on this.”

She was backed up by commentator Emily Sheffield, who said she had been at the recent Whitehall farming protest and those there were definitely not rich landowners.

Ms Sheffield insisted: “There were 15,000 farmers [at the protest] - not just rich people.”

“15,000 people don’t gather in the freezing rain - our teeth were chattering, there were a couple of old guys who passed out - they were not a bunch of rich landowners, these were people who literally feel you are threatening their farm, talk about £3m it’s completely wrong.”

“You’re hitting people whose herd is worth money and they are going to have to sell 20% of their farms just to pay a tax which is raising no money.”

Labour MP Mark Ferguson insisted he has “a lot of sympathy” for farmers but tax revenues do need to be raised to improve services for rural communities.

He added: “Everyone’s going to have to pay their part.”

Ms McVey pointed out that Labour is also giving hundreds of millions to overseas farmers rather than protecting British farmers.

The Tories are forcing a vote on the farming tax this afternoon, demanding a U-turn from the Government.

Shadow Environment Secretary Victoria Atkins said: “Labour’s vindictive family farm tax threatens to destroy British farming as we know it. Labour MPs have a choice to make.

“Will they vote to axe the tax and save the family farm? Or will they turn their backs on rural communities and back the Budget of broken promises?”

A spokeswoman for the National Farmers’ Union said: “We’re glad MPs will have a chance to properly debate this destructive family farm tax, and to show their farming constituents where they stand on it in a vote.”

“This is bad policy, built on bad data, with no consultation, and which punishes genuine food-producing family farms whilst failing to catch those who Government claims to be targeting.

“It deserves to be subject to the fullest scrutiny possible.”