Boris Johnson has put the prospect of a no-deal Brexit firmly back on the table, by introducing a legal provision to bar him from extending negotiations on a trade deal with Brussels beyond the end of next year.

The move was branded “reckless” by Liberal Democrat interim leader Sir Ed Davey, who warned it risked sending the UK “straight off the no-deal cliff”, threatening jobs, the environment and the NHS.

The ban, to be included in the Withdrawal Agreement Bill tabled in parliament on Friday, will prevent the prime minister from buying extra time if trade talks are not completed within what most experts regard as an extremely tight timescale. Last week a leaked recording revealed that Michel Barnier, the EU’s chief negotiator, believed the timetable was “unrealistic”. He told MEPs: “We will not get everything done in 11 months.”

And it will force businesses to consider once more whether they should make expensive contingency plans for a possible crash-out on World Trade Organisation terms on New Year’s Day 2021, having previously wasted money on abortive preparations for departure on 29 March and 31 October this year.

The withdrawal agreement reached by Mr Johnson with Brussels, due to take effect on 31 January, deals only with divorce arrangements and does not provide any guarantee of continued free trade after the end of a transition period running to December 2020.

Best pictures from Final Say Brexit march Show all 76 1 /76 Best pictures from Final Say Brexit march Best pictures from Final Say Brexit march Crowds march through central London Getty Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march Protesters gather in Parliament Square Led By Donkeys Best pictures from Final Say Brexit march Mayor of London Sadiq Khan joins protesters PA Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march People's Vote Final say march - 19 October 2019 Angela Christofilou Angela Christofilou/The Independent Best pictures from Final Say Brexit march 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Mr Johnson has previously vowed not to take advantage of the one- or two-year extension to transition on offer from the EU, but the new legal provision ties his hands, leaving him the options only of accepting whatever terms are offered to him by Brussels or facing the disruption to trade and transport links expected under no deal.

It breaches a promise made by the justice secretary, Robert Buckland, ahead of the election that MPs would be given a vote on whether to ask for extra time to stave off no deal.

A Downing Street source said: “Last week, the public voted for a government that would get Brexit done and move this country forward and that’s exactly what we intend to do starting this week.

“Our manifesto made clear that we will not extend the implementation period and the new Withdrawal Agreement Bill will legally prohibit government agreeing to any extension.”

Sir Ed responded: “This Tory government’s reckless approach to Brexit will send the country straight off the no-deal cliff.

“The only way Johnson can meet the December 2020 timetable is by giving up all his previous promises to Leave voters and agreeing to all the demands of the EU.

“Liberal Democrats will continue to stand up for Remainers up and down the country and oppose Brexit. People deserve better than a future where a prime minister willingly threatens jobs, the environment and the NHS.”

The move came after No 10 signalled that concessions on workplace rights and environmental protections made to MPs ahead of the election may not feature in the bill. A spokesperson told reporters that the legislation – known in Westminster as WAB – will reflect the agreement reached with Brussels in October rather than any later discussions.

The government carried out trials on handling lorry queues expected at channel ports in the case of no deal (Reuters) (REUTERS)

And Downing Street poured cold water on EU hopes that Mr Johnson’s 80-seat majority in the House of Commons will prompt him to seek a softer form of Brexit.

EU leaders including Ireland’s Leo Varadkar have indicated that they hope the PM will sign up to a “level playing field” on standards and regulations now that he is no longer dependent on the votes of Eurosceptic backbenchers in the European Research Group.

But the prime minister’s official spokesperson told reporters that Mr Johnson’s aim remains “a Canada-style free trade agreement with no political alignment”.

Negotiations will begin in the new year under the terms of a political declaration agreed by the UK and EU in October, which set out hopes for “an ambitious, broad, deep and flexible partnership across trade and economic cooperation with a comprehensive and balanced free trade agreement at its core”.

Mr Varadkar said last week that he wanted a deal which maintained tariff-free and quota-free trade as well as fair competition, and said he believed Mr Johnson was “probably in a similar space”.

Boris Johnson and Leo Varadkar met in Cheshire shortly before the withdrawal agreement was finalised in October (PA)

“I think the fact Mr Johnson has a clear majority makes a big difference,” said the taoiseach. “I think the prime minister’s hand is strengthened.”

EU leaders including Angela Merkel and Emmanuel Macron are concerned that UK divergence from European standards and regulations would give British companies an unfair competitive advantage in continental markets.

Divergence was the issue over which Mr Johnson walked out of Theresa May’s cabinet last year, as he believed her Chequers deal would tie the UK to following Brussels regulations in areas like workplace and environmental protections, animal welfare and public health.

A Canada-style agreement would allow Britain to set its own rules, potentially ripping up red tape to give businesses greater freedom and permit trade deals with countries like the US. But it would involve a degree of restriction of access to European markets.

And it would probably deal largely with goods, and not the vital services sector which makes up 80 per cent of the UK economy.

The PM’s official spokesperson insisted that the government believes it will be possible to secure a good free trade agreement within the 11-month deadline for a transition period after the UK formally leaves the EU on 31 January.

And he rejected suggestions that this would inevitably involve tariff barriers and that services would be excluded.

“What the political declaration sets out is that there is a joint aim from the UK and EU for tariff-free and quota-free trade,” said the spokesperson.