Jeremy Hunt has said both the government and Labour will have to compromise in order to come to a Brexit deal.
The foreign secretary said he did not think a permanent customs union, as favoured by Jeremy Corbyn, was a “sustainable, long-term solution”.
But speaking to BBC Radio 4′s Today programme on Tuesday morning, Hunt left open the possibility that a temporary customs union with the EU would be acceptable.
“I think this is a time when we have to be willing to make compromises on all sides because the message of last week was that voters for both main parties are very, very angry about the fact that Brexit hasn’t been delivered,” he said.
“I personally think that any kind of permanent customs union wouldn’t work in the long run because our economy is too big, but let’s see what the parties come up with.”
A number of senior Tory Brexiteers have said they would not vote for a customs union of any sort.
Hunt has previously warned that the PM would “lose more Conservative MPs than you would gain Labour MPs” if she made such a move.
Cross-party talks to find a deal are due to resume today following the local elections which saw both the Tories and Labour suffer losses.
Theresa May is under pressure set a firm resignation date ahead of a meeting with the chairman of the powerful 1922 Committee of Tory backbenchers.
Today’s meeting with Sir Graham Brady comes after the 1922 Committee requested “clarity” about the prime minister’s timetable for standing down and triggering a leadership contest.
Meanwhile, senior Tory activists will consider the question of May’s leadership at an emergency meeting of association chairmen next month.
The vote by members at an EGM of the National Conservative Convention would not be binding, but would add pressure on May to quit if passed.
In a message to members of the convention, reported by the Conservative Home website, chairman Andrew Sharpe said they would be asked to vote on a motion stating that “we no longer feel that May is the right person to continue as prime minister to lead us forward in the negotiations” and “therefore with great reluctance ask that she considers her position and resigns”.
May has said she will step down if her Withdrawal Agreement is ratified, but – with the deadline for Brexit extended to the end of October – has not made clear how long she intends to stay if no deal is reached.
Sir Geoffrey Clifton-Brown, treasurer of the 1922 Committee, put the spotlight on a departure date by insisting May announce a “road map” for her resignation after the European elections set for May 23.
On Sunday John McDonnell said he had no trust in May after reports emerged that she is ready to offer a temporary customs arrangement with the EU as part of the talks. He accused May of having “blown the confidentiality” of the talks.
A number of Labour MPs have demanded that any deal agreed by Labour and the government be put to a public vote.