The Brexit secretary has confirmed the government could try to turn indicative votes into binding decisions in a possible last-ditch attempt to break the Commons deadlock on leaving the EU.

The Guardian had revealed such a proposal was being considered as a plan B if talks with Labour failed to reach a compromise on Brexit.

Steve Barclay confirmed the move in an interview with BBC Radio 4’s Today programme. “If [the talks with Labour] fail the prime minister has said that we will come back to parliament … and seek to get a consensus on various options,” he said.

“We would have to agree through the usual channels how we [would make] votes more binding. The votes to date on the different options have been indicative.”

Under the plan, cross-party groups of MPs would be able to amend Theresa May’s withdrawal bill to bind the government into elements such as remaining in a customs union, which could then potentially gain a parliamentary majority for the deal.

“Both sides of the house need to compromise,” Barclay said, adding that the talks with Labour had been difficult. He also expressed the government’s continued opposition to a permanent customs union.

“I don’t think a permanent customs union is a good way forward. We have negotiated something better in the political declaration,” he said.

“What Labour have put forward is a unique model that is actually ruled out in treaty in EU law in terms of a third country having a say in the EU’s trade policy, but we are discussing that with them. We have put forward an approach which allows us to have the benefits of a customs union but also to have an independent trade policy.”

May’s request for a short extension to article 50 to 30 June looks likely to be rejected at an emergency summit in Brussels on Wednesday.

Barclay evaded questions about whether he could stay in a government that agreed to delay Brexit for a year. “I don’t want to see a delay for up to a year. But the key with any delay is that we are able to terminate it once we ratify in order that we can then get on and get a deal through parliament and leave the EU.”

Barclay also blamed parliament, rather the government, for the delay. “My constituents feel deep frustration that members of parliament, who stood on manifestos promising to leave, who voted to trigger article 50, are frustrating that vote.”

He conceded the EU was in control of the process at present, adding: “It is parliament that has forced this on the government.”