Boris Johnson has called for a swift end to any transition phase with Europe, in the latest in a series of provocative challenges to Downing Street’s Brexit strategy.

Speaking at the Foreign Office launch of the privately financed Institute for Free Trade, the foreign secretary urged that the two-year implementation period announced by Theresa May last week be kept short so that Britain was free to strike new trade deals with other countries.

“You can imagine what our brilliant companies are able to do … when they are finally – and let’s hope the date is soon upon us without too long a transition period – when they are finally unbound, unshackled,” Johnson told an audience of foreign ambassadors and business leaders.

Following similar interventions before May’s speech, the choice of venue for the launch – in the imperial splendour of the old Colonial Office map room – was widely seen as another provocative gesture. It implies official government support for a thinktank wedded to accelerating the point at which Britain can strike new trade deals, just days after May’s Florence speech advocated slowing the process down.

Daniel Hannan, the Eurosceptic MEP behind the new institute, immediately underlined his distance from the more cautious approach of the prime minister and Treasury by calling on Britain to embrace Singapore-style market liberalisation when it leaves.

May has gone out of her way to reassure EU leaders in recent days that Britain was not seeking to undercut the single market by adopting radical measures to become an offshore haven like Singapore.

“I’m looking at [the] high commissioner of Singapore [in the front row],” said Hannan. “They have gone from being half as rich as us to twice as rich as us. What was the magic formula? Just do it. They dropped their barriers.”

Michael Gove and the international trade secretary, Liam Fox, were also present to endorse the new institute, which Fox said showed the moral imperative to lower trade barriers.

“We may think the benefits of free trade are self-evident but we need to sell benefits to the public,” said Fox. “We have to go beyond the economics into the moral argument. As we leave the EU and take our independent seat at the WTO we will champion free trade.”

Hannan argued that the problem with selling trade liberalisation was a political one. “Free trade brings dispersed gains and concentrated losses,” he said. But he argued that Britain was at an “unfrozen moment” due to Brexit.

“It’s not every day a country of our size gets to draw up a new trade policy from scratch,” he said.

Both Hannan and the foreign secretary also attacked the new US trade sanctions against Bombardier, which Johnson called the “sad case of Boeing”, but joked that Britain has managed to sell an alternative product across the Atlantic.

“It’s only now that we are able to do free trade deals with the distinguished ambassadors here today,” he said. “We send sand to Saudi Arabia and bicycles to Holland … now we have been ingenious enough to export Nigel Farage to America.”

The Labour MP Pat McFadden, speaking for the Open Britain group which wants to maintain the closest possible links to the EU, accused May of being weak: “Any prime minister with an ounce of strength would not permit her cabinet colleagues to launch thinktanks undermining the government’s policy, let alone in a government building.



“But this just shows how weak Theresa May’s position has become. The Florence truce has not lasted long. Ideology over Europe has divided them before and it’s doing so today.

“But the key point is that this is not a game. The country’s future is at stake. And the economic interests of the country must come before the nationalist ideology to which too many ministers subscribe.”