In the same way, Brexit-backing Conservatives will flex their muscles if the EU insists there can be no new customs union unless Britain agrees not to seek outside trade deals.
The Prime Minister and her fellow Cabinet members have repeatedly stated their commitment to secure "friction-free trade" with the union after Brexit, claiming that Britain's future trade policy will be "more outward-looking than ever before".
Britain says its membership of the EU customs union, which now allows for the tariff-free movement of goods, will end along with its membership of the single market when it leaves the bloc in March 2019. We will leave the customs union and be free to negotiate the best trade deals around the world as an independent, open, trading nation.
"Companies will welcome the progress Government has made today in publishing these papers".
Officials in Brussels have made it clear that it is unwilling to begin negotiating a new trade relationship with the United Kingdom until an agreement is reached on the future rights of European Union nationals, and the border between Northern Ireland and the Republic.
A "temporary" customs union with the EU is one of the options being considered by British officials in a bid to avoid a Brexit cliff-edge come March 2019, the Government has revealed.
On Sunday, Liam Fox and Philip Hammond, the latter previously regarded as a champion of a "soft Brexit", published a joint statement in the Sunday Telegraph saying Britain would be outside the customs union during the post-Brexit transition phase and at that point it would be "a "third country", not party to the EU treaties".
Turkey already has its own customs union with the EU for industrialised goods, which enables participation in complex manufacturing supply chains.
According to the proposal, Britain would be able to start work on new trade deals during the interim phase.
In particular it is hard to hold substantive talks about the future of the land border between Northern Ireland and the Irish Republic - another of the EU's early demands - without knowing what the customs relationship will be.
"These fantastical and contradictory proposals provide no guidance for negotiators or certainty for businesses". The government will publish further proposals on the Irish issue on Wednesday.
"No matter how they try to dress it up, the Conservatives are now heading for a chaotic Brexit that will leave Britain poorer".
Britain wants to use smart technology and spot checks to police the flow of goods between the two countries after Brexit, angering the Irish Government.
The CBI's deputy director, Josh Hardie, welcomed the publication of fresh details of the government's aims for a new customs deal.
DExEU says the interim customs arrangements will be "time-limited" to allow for businesses to adapt to a post-Brexit system.
"The proposals also make it less likely that necessary transitional arrangements will be in place by March 2019".