LONDON (Reuters) - Britain will face a shortage of fuel, food and medicine if it exits the European Union without a transitional agreement, government documents leaked to the Sunday Times showed.
The report by the Cabinet Office identified the most likely effects of Brexit without an agreement, not the worst-case scenario, the newspaper said.
But Michael Goff, the minister in charge of coordinating preparations for an exit without an agreement, rejected that, saying the documents represented the "worst-case scenario" and that the government had accelerated planning for exit in the last three weeks.
The paper said that up to 85% of trucks using the main transit routes of the English Channel "may not be ready" to pay French customs duties, which means that the unrest in the ports may continue for up to three months before the movement of goods to improve.
The government also believes barriers are likely to be set up between Northern Ireland and the EU member Republic of Ireland, where current plans to avoid expanded inspections will prove unsustainable.
The dossier "prepared by the Ministry of Cabinet Affairs this month as Operation Yellowhamer ... gave a rare glimpse into the government's secret planning to avoid a catastrophic collapse of the country's infrastructure," the newspaper said.
"The dossier, which has an official-sensitive classification, which means that access to it requires a security clearance, is very important because it is the most comprehensive assessment of Britain's readiness to leave the EU without an agreement."
"Yellowhammer is the worst case scenario," Goff replied on Twitter to one of the journalists who wrote the article in the Sunday Times. "Significant strides have been made in the last three weeks to accelerate the pace of EU exit planning.
Prime Minister Boris Johnson's office said he did not comment on the leaked documents.
A government source blamed the leak on an unnamed former minister, adding he wanted to influence negotiations with the EU.
"This document dates from a time when ministers were blocking what to do to prepare for exit and the money was not available. A former minister deliberately leaked it in an attempt to influence discussions with EU leaders," said the source, who declined to be named.
"I think there is a lot of panic spreading, and a lot of people are playing on the chord," Energy Minister Kwasi Korten told Sky News when asked about the documents. "We have to prepare (without) an agreement."
"We will be fully prepared to withdraw without agreement on October 31," he said.
Britain's Gibraltar government said the warnings contained in the documents about its ability to cope with the country's exit from the bloc without agreement were wrong and outdated.
"We have dealt with all issues related to the flow of goods, food, waste, medicines and the movement of people and vehicles across the border," Gibraltar Prime Minister Fabian Picardo said in a statement.
A group of more than 100 Johnson lawmakers wrote to invite him to announce an urgent recall of parliament to discuss the situation.
"We are facing a national emergency," the letter said. "Parliament should now be summoned in August and kept in permanent session until October 31 so that the voices of the people can be heard and that your government can be properly monitored."
Johnson is due to tell French President Emmanuel Macron and German Chancellor Angela Merkel this week that the British parliament cannot stop his exit from the European Union and the EU should negotiate and agree on a new deal if it wants to avoid a British withdrawal from the bloc without a deal.
Johnson is under pressure from politicians from across Britain's political spectrum to prevent an unprepared withdrawal of the country.