Ministers have “fiddled the figures” to disguise the true level of chaos at British ports from a no-deal Brexit, it has been alleged.

The government’s Operation Yellowhammer dossier – only released after a parliamentary battle – predicted a “low risk of significant sustained queues” at ports other than in Kent.

But new documents have revealed this would only be the case because tens of thousands of vehicles would be turned away before they reached the coast, for not having the correct paperwork.

In Liverpool, Holyhead and Portsmouth about two-thirds of vehicles would not be allowed into the port, the Department for Transport (DfT) papers, stamped “official sensitive”, show.

Andy McDonald, Labour’s shadow transport secretary, said the DfT was “not being straight with the public” by only publishing assumptions that were “practically meaningless”.

“Much of the analysis only seems to consider those vehicles which have the correct paperwork and totally overlooks the impact of those HGVs which won’t,” he protested.

And Jo Stevens, a Labour supporter of the People’s Vote campaign, said: “The revelation that the government appear to have fiddled the figures to make the calamity of no deal look less damaging is another sign of the behaviour which has led to a complete breakdown of trust in Boris Johnson.

Supreme Court protests: Boris Johnson's prorogation legal or not? Show all 15 1 /15 Supreme Court protests: Boris Johnson's prorogation legal or not? Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters gather outside The Supreme Court ahead of a hearing on the legality of Boris Johnson's proroguing of Parliament Getty Supreme Court protests: Boris Johnson's prorogation legal or not? The supreme court justices will sit as a panel of 11 judges to hear the challenge, brought by campaigner Gina Miller, that the Prime Minister acted unlawfully when he advised the Queen to suspend parliament AP Supreme Court protests: Boris Johnson's prorogation legal or not? A woman protests outside the Supreme Court Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? The PM sent lawmakers home on 9 September until 14 October, just over two weeks before the UK is due to leave the European Union AP Supreme Court protests: Boris Johnson's prorogation legal or not? Gina Miller arriving AP Supreme Court protests: Boris Johnson's prorogation legal or not? People protest outside the Supreme Court Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Boris Johnson likened himself to the Incredible Hulk days previous as he promised to ignore the Commons legislation ordering him to delay Brexit if negotiations break down PA Supreme Court protests: Boris Johnson's prorogation legal or not? Officials bring in documents Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? People protest outside the Supreme Court of the United Kingdom during a hearing on Prime Minister Boris Johnson's decision to prorogue parliament, in London, Britain September 17, 2019. REUTERS/Phil Noble PHIL NOBLE Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? Joanna Cherry of the Scottish National Party leaves the Supreme Court Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Demonstrators protest outside the Supreme court in central London on the first day of the hearing into the decision by the government to prorogue parliament on September 17, 2019. (Photo by Tolga Akmen / AFP)TOLGA AKMEN/AFP/Getty Images TOLGA AKMEN AFP/Getty

“The only hope that Johnson has of meeting his claims about the ports is to turn away vast numbers of lorries before they get there. That means lost orders, lost money and eventually lost jobs.”

The DfT declined to comment on the documents, revealed by the Financial Times, but insisted there “should be limited disruption” if hauliers had “the correct documentation”.

“We have implemented a major campaign to ensure hauliers can take action to get ready and are able to operate and that trade can continue to move as freely as possible between the UK and Europe after Brexit,” a spokesperson said.

However, the documents, dated last month, set out how only a minority of the normal “flow rate” of vehicles will be allowed into the ports, if the UK crashes out of the EU with no agreement on 31 October and EU countries impose import controls.

“One hundred per cent of non-compliant vehicles will be turned away, which means the resulting flow rate is 29 per cent at Holyhead, Heysham and Liverpool, and 32 per cent at Portsmouth,” one states.

Meanwhile, at Dover, the busiest port for traffic to and from the EU, the queues could reach a peak of 8,500 vehicles, according to one of the documents seen by the FT.

It calculated that, given the typical 16.5m length of an articulated lorry, the tailbacks outside Dover could stretch to about 150km.

One document said imports would only be able to flow freely at Portsmouth if there were “local arrangements preventing HGVs that have been turned back from blocking inbound flow”.