Tory Shadow Environment Secretary Victoria Atkins said: “I have repeatedly raised, both in the House of Commons and outside of it, the tragic stories shared with me about the human cost of this cruel tax.
“Keir Starmer cannot pretend he doesn't know the damage this will do to the lives and livelihoods of farmers.
“He must now keep his pre-election promise to farmers and ax this vindictive tax.”
Reform UK Deputy Leader Richard Tice added: “The fact that Sir Keir Starmer is determined to press on with his tax on family farms despite the very stark warnings he's had just goes to show how cruel and vindictive Labour's war on our farming community is.
“Family farms are the backbone of British agriculture, and should be supported, not taxed to death. Only Reform stands up for our farmers and will scrap the family farms tax.”
Mo Metcalf-Fisher, director of external affairs at the Countryside Alliance, said the “incredibly heartless remarks” were “made in defense of the indefensible”.
He added: “The Prime Minister should stop, listen and reflect on the outpouring of concerns from the rural community and his own MPs and immediately reset his relationship with the countryside by rethinking this disastrous policy before it's too late.”
The Government has faced an ongoing backlash for slapping inheritance tax on farms worth over £1 million in Chancellor Rachel Reeves's first budget, with the changes due to be implemented next April.
Sir Keir was asked about the policy during his appearance before the Liaison Committee, which is made up of senior parliamentarians who chair the various Commons committees.
Senior Labor MP Cat Smith asked if the Prime Minister was “aware that some farmers who have a terminal diagnosis are now actively planning to expedite their own deaths”.
Sir Keir replied: “I've had discussions with a number of individuals who have drawn all manner of things to my attention.”
Ms Smith said farmers who backed Labor at the last general election felt “misled” by the changes which will “pull the rug from underneath farming communities and obliterate the family farm for many farmers”.
The Labor MP for Lancaster and Wyre added: “We're in a situation now where elderly farmers or farmers with a terminal diagnosis and are in a position whereby if they die before April their farm will be passed to the next generation with no tax implications but if they die after the potential of their family farm being completely unviable.
“Can you see how farmers can feel like this government has not necessarily treated them the way they expected to be treated as working people?”
The Prime Minister replied: “I do understand the concern, and I met with the president of the National Farmers' Union just last week, as I've met with him before, to run through the particular concerns they have.
“I do think on agricultural property relief, there had to be sensible reform. And I think this is sensible reform.”
Lib Dem MP Alistair Carmichael, who chairs the Environment, Food and Rural Affairs Committee, added: “Nobody should be left feeling – as Cat Smith has just described – that they would be better off dying between now and next April.”
Sir Keir replied: “No, of course. But governments have to bring about sensible reform.”
Mr Carmichael urged Sir Keir to abandon the policy amid criticism from his own MPs.
The Liberal Democrat MP said: “You don't have to listen to me. You don't even have to listen to the farmers out there. You don't have to listen to the president of the NFU. But why do you not listen to your own party colleagues?”
Sir Keir said: “I do listen to party colleagues all the time.”
The Chancellor limited the existing 100% relief for farms to only the first £1 million of combined agricultural and business property in last year's autumn budget.
But critics have warned that the policy could spell the end of family farms across the country.
Markus Campbell-Savours, a rural Labor MP, was stripped of the party whip earlier this month for voting against the inheritance tax plans.
The Government has insisted the changes, which are expected to bring in around £500 million a year for the Treasury, will not affect the majority of farms.
The Daily Express has campaigned for a U-turn with our Save Britain's Family Farm crusade.
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