A confidential government dossier warning of the impact of a no-deal Brexit was described Sunday as a worst-case scenario document.

Michael Gove, the cabinet minister tasked by Prime Minister Boris Johnson with preparing for a no-deal departure by Britain from the European Union, commented after details from the dossier were published in London by the Sunday Times.

The Times said the report has been compiled by the Cabinet Office and offered a rare glimpse into the covert planning being carried out by the government to avert a catastrophic collapse in the nation's infrastructure.

The confidential report, codenamed Operation Yellowhammer, warned of shortages of foods and medicines, with food prices rising. It also said Britain could face months of disruption at its seaports after a no-deal Brexit. It also spoke of a hard border between Ireland and Northern Ireland after plans to avoid checks fail, sparking protests.

There would also be the possibility of delays at EU airports, the Channel Tunnel and at Dover, the main port from Britain for mainland Europe.

Gove said the government study was old, and since Johnson took over at 10 Downing Street, planning for a no-deal Brexit has been accelerated.

He added that very significant steps have been taken in the last three weeks to accelerate Brexit planning.

Gove, in a message on his social media website, said: "We don't normally comment on leaks - but a few facts - Yellowhammer is a worst case scenario. Very significant steps have been taken in the last three weeks to accelerate Brexit planning."

Interviewed by journalists outside his London home, Gove said: "It's certainly the case that there will be bumps in the road, some element of disruption in the event of no-deal. But the document that has appeared in the Sunday Times was an attempt, in the past, to work out what the very, very worst situation would be so that we could take steps to mitigate that. And we have taken steps."

The Daily Telegraph said it had been told by Downing Street that the dossier had been leaked by a former minister in an attempt to influence discussions with EU leaders.

Later this week Johnson is to meet with German Chancellor Angela Merkel and French President Emmanuel Macron, with media reports in London saying he will insist there must be a new Brexit deal to avert a no-deal Brexit.

The minority Liberal Democrats said the Operation Yellowhammer documents revealed that a no-deal Brexit had "wartime implications, in peacetime, all of them self-inflicted".

Tom Drake, the party's Brexit spokesman at Westminster, said: "People will be horrified that Boris Johnson and the Conservatives are willing to pursue a plan that will lead to shortages of medicines, food and fuel."