BIRMINGHAM, England

British Prime Minister Keir Starmer has ruled out joining a new customs union with the European Union, arguing it would be “not sensible” to unravel the trade agreement signed with the US in May.

Starmer made the remarks in parliament on Wednesday after Liberal Democrat leader Sir Ed Davey pressed him to revisit the government’s post-Brexit stance.

Davey has called the UK’s new US national security alignment “deeply concerning” and urged Starmer to make clear to Washington that interference in European democracy would be unacceptable. He also asked the prime minister to consider opening talks with Brussels on customs arrangements.

More than a dozen lawmakers from the ruling Labour Party have backed a Liberal Democrat bill calling for negotiations with the EU and a rethink of the UK’s Brexit strategy.

Starmer dismissed the proposal, saying Labour campaigned on a commitment not to rejoin a customs union or the single market.

Turning to the issue directly, Starmer said the UK had secured “a better deal with the US than with any other country,” and warned that entering an EU customs union could jeopardize that agreement.

“It would not be sensible to unravel that by joining an EU customs union,” he told the MPs.

Despite ruling out a formal customs pact, Starmer said his government intends to deepen cooperation with European partners and strengthen the overall UK-EU relationship.