And challenged over which side she would back in Wednesday's Commons vote if she were a backbencher, she said: "I'm committed to the Government's position, which to some extent we are still working on".
Shadow Brexit Secretary Sir Keir Starmer said: "Over the past few weeks it has become abundantly clear that Theresa May is unwilling and unable to put the country's interests first during the Brexit negotiations".
European Union negotiators last week gave a "detailed and forensic rebuttal" to the feasibility of two options put forward by Prime Minister Theresa May in her Mansion House speech last month.
Prime Minister Theresa May wants to pull Britain outside the EU's customs union area but avoid erecting a "hard border" between Ireland and Northern Ireland. The so-called "Withdrawal Agreement" mapping most of this out is set to be cleared at an European Union leaders' summit next October.
Lawmakers debated yesterday whether Britain should stay in a customs union with the EU after Brexit, as supporters reported growing parliamentary opposition to the government's plans for future ties with the bloc.
May says Britain must leave the EU customs union, which sets external tariffs for goods imported into the bloc, so that it can independently negotiate trade deals with other countries. This May's senior consultants now secretly yield that a U-turn could be unavoidable with one supposedly telling a gathering a month ago that the head administrator and her best group won't cry into the brew on the off chance that they are compelled to reconsider cutting traditions ties with the EU.More news: Costa absent from final Atletico training ahead of travel for Arsenal tie
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"This comment will take the Windrush heat off her now for a couple of hours".
Deputy chief executive James Hookham said: "Leaving the EU Customs Union and single market has big consequences for supply chains and the continuity of the UK's European trade. We are leaving the customs union, we are not joining a customs union".
Staying in the trading bloc also risks a domestic political crisis as Brexit backers in May's Cabinet have long said that being able to strike new trade deals independently from the European Union is a major benefit of Brexit.
"There is a discussion around which of the two customs options.the government opts for but are we leaving the customs union?".
In light of the Government's own impact assessments and the lack of progress on any new trade deals, any economic case for ruling out a customs union has collapsed.
Mr Dodds said if the North was treated any differently from any other part of the United Kingdom under Brexit, his party would vote against Mrs May's minority government which they have been propping up in office.