Ministers are desperately drawing up contingency plans to tackle food shortages if farmers strike over inheritance tax changes.

Transport Secretary Louise Haigh said the Government would ensure food security if it faces militant action over the plans.

Some farmers have warned that they could stop production which could empty supermarket shelves and prompt panic buying.

Asked about contingency plans for food security if farmers strike, Ms Haigh told Sky’s Trevor Phillips: ‘The Department for Environment and Food and Rural Affairs will be setting out plans for the winter and… setting out contingency plans and ensuring that food security is treated as the priority it deserves to be.’

She said that although the Government recognised the ‘difficult situation’ that many were in, the IHT changes were ‘fair and proportionate’.

She ducked questions about why the PM failed to address protesting farmers at Welsh Labour conference on Saturday.

Chancellor Rachel Reeves announced changes to inheritance tax at the Budget that will mean farms worth more than £1million will be liable for the charge of 20per cent.

She has argued that it will only affect a handful of farms worth more than £3million once other allowances have been used.

But the National Farmers’ Union (NFU) said the Government’s own figures suggest two-thirds of businesses could be hit.

Hundreds of farmers will protest in London tomorrow [TUE] over the changes they say could lead to the break-up of family businesses.

Sir Keir said yesterday that while he understood their concerns, the move would not affect the vast majority of farms or farmers.

Asked about the protests, he said: ‘They are entitled to express their views. I do understand their concerns.’

And farming minister Daniel Zeichner urged farmers to ‘look calmly’ at the Government’s plans.

But the head of the National Farmers’ Union (NFU) Tom Bradshaw warned that farmers were feeling ‘angry and betrayed’.

‘We have a Government saying food security is a critical part of national security, yet they’ve ripped the rug out from that very industry which is going to invest in food security for the future,’ he told Sky News’ Sunday Morning with Trevor Phillips.

However, he said he did not ‘for one moment condone’ withholding food from supermarkets in protest.

‘That is not an NFU tactic, we do not support emptying supermarket shelves, but I do completely understand the strength of feeling that there is amongst farmers, they feel helpless today, and they’re trying to think of what can they do to try and demonstrate what this means to them,’ he added.

Clive Bailye ((CRCT)), founder of The Farming Forum and one of the organisers of tomorrow’s rally, warned of strikes, blockades and go-slows if ministers didn’t pay attention to farmers’ anger.

He said it had been ‘disappointing’ to hear the ‘arrogant’ Prime Minister ‘doubling down’ at Labour’s conference in Wales on Saturday where he promised to defend last month’s Budget ‘all day long’.

‘There’s a lot of militancy in the farming community over this,’ said Mr Bailye, an arable farmer in Staffordshire.

‘If we don’t get anything out of Tuesday’s rally I can see things getting bad very fast.

‘If the next generation can’t afford to continue with the farming way of life then they’ve got nothing to lose.

‘That makes them very dangerous – farmers have got the ability to cause economic chaos.’

He added: ‘We’ve seen how European farmers have managed to get their governments to change policy.

‘Talk of a farmers’ strike is really gathering momentum, and you could see blockades or go-slow protests.

‘If farmers tip away their own milk, they’re the ones who lost out the most – but if they feel they’re going to go out of business then they may go ahead anyway.

‘But we don’t want to cause disruption to the public because at the moment they’re on the side of farmers.’

Mr Bailye predicted that as many as 25,000 angry farmers would descend on the capital tomorrow where they will be addressed by politicians as well as TV star turned farmer Jeremy Clarkson.

Gareth Wyn Jones, a Welsh farmer who has been leading calls for a strike, said he would stop supplying his sheep and cattle for a week from today.

He predicted shortages of bread, milk and eggs in the coming weeks if ministers don’t agree to negotiations.

‘We need to show the Government that if we’re not going to listen, we will turn off the taps of food production. Everything starts at the farm gate,’ he told the Mail.

While organisers can’t yet say how many will heed calls for a strike this week, Mr Wyn Jones said there had been ‘massive’ support for the plan among Welsh farmers who rallied on Saturday.

‘If ministers aren’t careful they will have awakened the sleeping giant of farming.’