Boris Johnson has warned it would be “mad” to end up with a Brexit settlement that does not allow the UK to enjoy the “economic freedoms” of leaving the European Union.

Signalling the need to diverge from EU rules after leaving the bloc, Mr Johnson insisted that the UK should not remain locked into alignment with Brussels.

In the latest salvo in a Cabinet battle over how closely the UK should remain tied to the EU after leaving, Mr Johnson said Britain should not be “lashed to the minute prescriptions” of a bloc comprising just 6% of the world’s population.

Mr Johnson’s comments at a speech in London are in stark contrast to Chancellor Philip Hammond’s hope that the UK would only diverge “very modestly” from the EU.

With the Cabinet set to make a final decision on its approach, Mr Johnson refused to guarantee he would not quit this year if there was a plan for close alignment.

“We are all very lucky to serve and I’m certainly one of those,” he said.

Boris Johnson's speech: key words and phrases
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The UK has committed to leave the single market and customs union, but the EU could impose conditions to closely follow rules as part of the comprehensive deal sought by Theresa May.

Setting out his approach, Mr Johnson said: “We would be mad to go through this process of extrication from the EU and not to take advantage of the economic freedoms it will bring.”

By leaving the EU “we will be able, if we so choose, to fish our own fish, to ban the traffic in live animals and payments to some of the richest landowners in Britain”.

There would be freedom to cut VAT on fuel, “simplify planning and speed up public procurement”.

In a sign that there could be changes to environmental protections, Mr Johnson said “we might decide that it was indeed absolutely necessary for every environmental impact assessment to monitor two life cycles of the snail and build special swimming pools for newts” but “it would at least be our decision”.

Former Lib Dem MP Sarah Olney joins protesters on the second floor balcony at Lib Dem headquarters next door to the Policy Exchange in London ahead of Mr Johnson's speech (Dominic Lipinski/PA)
Former Lib Dem MP Sarah Olney joins protesters on the second floor balcony at Lib Dem headquarters next door to the Policy Exchange in London ahead of Mr Johnson’s speech (Dominic Lipinski/PA)

Mr Johnson said the issue was about “who decides” and “it may very well make sense” to remain in alignment with EU standards on some products – but that commitment should not be written in to the Brexit deal.

“I don’t think we should necessarily commit, as a matter of treaty, that forever and a day we are going to remain locked into permanent congruence with the EU,” he said.

In an effort to address concerns about the potential hit to trade, Mr Johnson said: “To those who worry about coming out of the customs union or the single market – please bear in mind that the economic benefits of membership are nothing like as conspicuous or irrefutable as is sometimes claimed.”

Outside the EU the UK will be able to do “serious free trade deals” with growing economies around the world.

Mr Johnson rejected arguments for a second referendum and warned that it would be a “disastrous mistake” to seek to thwart Brexit.

In a message to Remain supporters, the Brexit-backing minister said leaving the EU could be “grounds for much more hope than fear”.

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He insisted that Brexit would not make the UK more “insular” and Britain would remain a “magnet” for talented migrants.

But stressing the ability to control the UK’s borders, he said “we need to ask ourselves some hard questions about the impact of 20 years of uncontrolled immigration by low-skilled, low-wage workers”.

Mr Johnson’s speech, aimed at reaching out to Remain supporters, did little to win over Tory critics.

Sarah Wollaston said Mr Johnson’s upbeat speech did not address the “serious practical difficulties” posed by Brexit.

Former minister Anna Soubry said he “fails to understand the very real concerns of British business”.

The speech is the first of six being made by the Prime Minister and senior Cabinet figures to set out the Government’s road map for Brexit.

Brexit Secretary David Davis, International Trade Secretary Liam Fox and Mrs May’s deputy David Lidington are expected to speak in the coming weeks.

It follows criticism of the Prime Minister for failing to spell out Britain’s Brexit aims.

The Chancellor, a prominent Remainer who is not on the list of set piece speeches, is on a tour of European capitals aimed at building business and political ties.

Philip Hammond is on a tour of European capitals (Toby Melville/PA)
Philip Hammond is on a tour of European capitals (Toby Melville/PA)

The Chancellor used a piece in Swedish newspaper Dagens Industri to call for continued “close connections” with the EU and a deal that covers financial services.

But he also urged the EU27 states to be clearer about their approach to the talks.

He said: “The complaint from Brussels has been that the UK ‘hasn’t made up its mind what type of relationship it wants’, but in London, many feel that we have little signal of what future relationship the EU27 would like to have with a post-Brexit Britain.

“I don’t believe this can be a question only for British politicians and British voters to resolve.”

In a sign of the EU27’s frustrations, a spokesman for German chancellor Angela Merkel said: “It’s important for us that Britain concretise its plans … time is running out.”