Labour has faced fresh accusations of a muddled Brexit policy after Sir Keir Starmer refused to back his deputy leader on whether Britain could stay in the single market after Brexit.

Starmer, the shadow Brexit secretary, said Britain could attempt to be in “a customs union”, but said it could not be in the customs union as a non-EU member.

His comments are at odds with Tom Watson who said on Thursday that the country could permanently remain part of both the single market and customs union after Brexit, stating that membership of both “might be a permanent outcome of the negotiations”.

But Starmer said Labour wanted a “partnership” with the bloc that “retains the benefits of the single market and the customs union”.

“We