LABOUR high command has been challenged over its "confusing" stance on Brexit after leading figures appeared at loggerheads over the party’s official position.

Barry Gardiner, the Shadow International Trade Secretary, insisted remaining in the European customs union after Brexit would be a "disaster" as it would leave the UK bound by EU free trade deals but without achieving the benefits.

His comments came after Jeremy Corbyn at the weekend admitted the party had yet to decide its official position on future customs arrangements while Sir Keir Starmer, the Shadow Brexit Secretary, has said membership of the customs union should remain on the negotiating table.

Mr Gardiner told BBC Radio 4’s Westminster Hour: "We leave the customs union because only member states of the European Union are members of the customs union.

"Other countries like Turkey have a separate customs union agreement but the trouble with that is that it gives you an asymmetrical relationship with the third party countries that the EU does a deal with.

"So the EU could do a deal with another country - let's say America - which we would be bound by in the UK; we would have to accept the liberalisation of our markets, we would have to accept their goods coming into our markets on the terms agreed by Europe, which could be prejudicial to us but we would not have the same access into America's markets, we would be bound to try and negotiate it but why would America give us that access when it's got all the liberalisation of our market that it wants. It's a disaster."

The Scot also dismissed the idea of Britain remaining in the single market under a Norwegian-style agreement, saying it would leave the UK like a "vassal state," ie paying money to Brussels without any say over the rules.

But Labour’s Carwyn Jones, the Welsh First Minister, insisted there was no need to leave the single market when Britain left the EU.

"I went to Norway in January, they are not members of the EU but they have almost full access to the single market. You don't have to leave the EU and leave one of the world's biggest markets at the same time.

"That's an interpretation that's been put on the result by the current UK Government and that makes no sense at all," he declared.

But the SNP challenged Scottish Labour to explain the party’s position on the single market after it said a “rift” had opened up between its leading figures.

Joan McAlpine, the SNP MSP, said: “Labour are deeply divided on this fundamental issue and Kezia Dugdale needs to explain where Scottish Labour stand.”

She claimed Mr Corbyn was now not only mimicking the “inflammatory language” of Ukip and the Conservatives on immigration but also seemed unaware of the distinction between single market membership and EU membership.

“It is not only entirely possible for the UK to remain a member of the single market even after Brexit, it is absolutely essential to do so to protect thousands of jobs and our living standards,” declared the Nationalist MSP.

“Kezia Dugdale used to say that Scottish Labour were ‘absolutely committed’ to retaining our single market membership. It’s time for her to explain whether she backs her colleague Carwyn Jones or whether she’ll follow Jeremy Corbyn’s lead and dance to UKIP’s tune,” added Ms McAlpine.

Meanwhile, Labour MP Chuka Umunna, a prominent Remain campaigner, said there should be "clear red water" between his party, the Tories and Ukip over Brexit.

"Taking single market and customs union membership off the table in the Brexit talks is the Tory position, it should not be Labour's," argued the London MP

Responding to Mr Gardiner's comments directly, fellow Labour MP Wes Streeting said: "Where has this come from? We were told customs union is still on the table. Even the Tories are keeping this option open."

Elsewhere, one senior Labour MP admitted, given the "confusing" and "conflicting" frontbench views: “Even I don’t know what the party’s official position is any more.”