Britain's Chancellor of the Exchequer, Philip Hammond, arrives back in Downing Street in central London, Britain June 13, 2017. REUTERS/Stefan Wermuth

LONDON (Reuters) - Chancellor Philip Hammond will argue for Britain to stay in the European Union’s customs union, in a bid to soften Brexit and alter Prime Minister’s Theresa May approach, The Times reported on Tuesday citing several unidentified sources.

In January, May outlined her vision of a clean break with the EU, saying that she wanted Britain to be able to make its own trade deals while maintaining trade with Europe that was as “frictionless as possible”.

Hammond, whose position as chancellor was reported to be under threat before the election, is seen as one of the most pro-EU members of May’s cabinet.

He will attempt to change May’s mind on leaving the customs union after a disastrous election in which the government lost its majority last Thursday, the newspaper said.

The report said Hammond believes the government must rethink its plan to pursue an independent trade policy outside the customs union.

A Treasury spokeswoman declined to comment on the report.

The EU customs union guarantees tariff-free trade within the bloc but prohibits members from striking third-party trade deals.

After May’s decision to call an election to obtain a mandate for her vision of Brexit backfired, she is facing pressure to soften her approach to leaving the bloc.

Earlier on Tuesday, senior British minister Michael Gove had said that Britain would leave the customs union, in line with government policy before the election.