Food producers have warned of vegetable shortages lasting three months, while emergency planners are concerned failing to land an agreement with Brussels will spark panic-buying worse than that seen during the first lockdown.
Speaking to The Times, a senior consultant to one of the biggest supermarkets said: "There was a conversation a week ago when ministers said prepare for no-deal.
“This weekend the message is that it's no-deal.
"Supermarkets and ministers are hugely worried about panic-buying.
“They saw what happened over Covid when people started hoarding toilet rolls and know how quickly it can go wrong.
"That will be nothing compared to what will happen.
“Meat supplies will be fine and fruit comes from South America but there are likely to be shortages of vegetables for three months."
Today Scotland Office minister David Duguid insisted the only inconvenience shoppers would face was over "the specific shape of pasta".
Appearing on the BBC's Politics Scotland, the Banff and Buchan MP claimed he didn’t “recognise” the claims.
He said: “There is a lot of scaremongering going around not least by the SNP and others.”
Asked to guarantee no shortages in the event of a No-Deal, he said: “Well, I'm not going to guarantee anything that's hypothetical.
“In the same way if you look back on the Covid crisis that we’re still experiencing, and we went through the peak of earlier this year - and by the way, I would take this opportunity, I don't like to miss any opportunity to thank our fabulous food supply chain, whether it's primary producers or our retailers or our shop workers in managing to maintain that food supply.
“You may not get the specific shape of pasta you like but there will not be the kind of shortages that I think is being reported.”
The warning comes one day on from lorries being backed up for three miles on the A20 outside Dover yesterday, after Calais suffered 10-mile tailbacks on Friday.
Richard Burnett, chief executive of the Road Haulage Association, explained the queues were "highly unusual at this time of year", adding: "It's a sign of [what will happen] when we do start to [see] checks and paperwork.
“The stock building is also real, we wouldn't normally see this level of volume."
Government officials insist they have done enough to secure supplies of food and medicines through the new Border Operations Centre, which will monitor the flow of goods.
A source added: "No one needs to worry about food, medicine or supply chains."
It comes as the two sides agreed the Brexit talks will continue with negotiators set to miss yet another deadline.
Boris Johnson spoke to European Commission president Ursula von der Leyen today and agreed to carry on talking, despite saying talks would go no further than today.
In a joint statement they vowed to “go the extra mile” in an effort to avoid a no deal outcome on January 1.