Britain put the prospect of a chaotic Brexit back on the table on Thursday as it set out its red lines for upcoming trade talks with the European Union.
In its mandate for negotiations that start on Monday, Prime Minister Boris Johnson's government rebuffed the EU's demands for common trading standards and to maintain existing fishing rights.It set out hopes for a free trade deal with Brussels, but warned it could walk away without one if a "broad outline" of an agreement has not emerged by June.
This would see Britain's currently seamless trading arrangements with the EU, forged over half a century of membership, end once a post-Brexit transition period expires in December.
"We want the best possible trading relationship with the EU, but in a pursuit of a deal, we will not trade away our sovereignty," senior government minister Michael Gove told MPs.
The European Commission, which is negotiating on behalf of the EU's 27 member states, said it was preparing for all scenarios.
"The commission maintains its capacity to prepare for no deal following the result of those negotiations," spokeswoman Dana Spinant said.
Britain left the EU on January 31, but both sides agreed to a standstill transition period lasting until December 31 to allow time to strike a new partnership.Johnson wants a free trade agreement similar to the EU's deal with Canada, set alongside separate agreements laying out cooperation on issues such as fishing, energy, aviation and law enforcement.
But Brussels says Britain's geographical proximity and existing close ties make it a different case, fearing it could gain an uncompetitive advantage by relaxing costly environmental and labour laws.
It says Britain must mirror EU standards if it wants to continue freely trading goods with the bloc's huge single market.
However, London says this would constrain its ability to strike deals with other countries, notably the United States, whose Trade Representative Robert Lighthizer visited London on Thursday.
UK International Trade Secretary Liz Truss said she told US President Donald Trump's envoy that "securing an ambitious free trade agreement with the US is one of my top priorities".
Brussels also wants its state aid rules to apply in Britain -- something London rejects.
Another potential flashpoint is financial services, which could be a bargaining chip for Brussels because of the importance of the sector to the British economy.
London wants to complete so-called equivalence assessments by June, to allow firms to keep working in the EU after December.
As Gove set out the government's plan in the House of Commons, opposition politicians decried the hard line approach.
"This is nothing other than a routemap to the cherished no-deal -- the real ambition of these Brexit zealots," said Scottish National Party MP Pete Wishart.
There was also criticism at confirmation that Britain will leave the European Arrest Warrant scheme, which allows for the swift transfer of suspects across the bloc.
The British government said it wanted to reach its own, separate fast-track extradition arrangement with Brussels.
But Labour MP Yvette Cooper, chairwoman of the home affairs committee, said it represented a "huge scaling back in ambition" for a close security partnership.
Another area of controversy is fishing rights, which became a totemic issue for the Brexit campaign led by Johnson during the 2016 EU referendum campaign.
It is also vital for many EU countries, notably France, where fish and seafood caught in UK waters account 30 percent of sales for fishermen.
Brussels wants to maintain the right of its fleets to fish in UK waters, and has warned that failure to agree on this could scupper the wider trade talks.
But Gove told MPs: "We will take back control of our waters as an independent coastal state and we will not link access to our waters to access to EU markets."
London proposes instead that fishing opportunities be negotiated annually, based on stock levels.