World Bulletin / News Desk

Britain's opposition Labour Party warned on Sunday that it could team up with Conservative rebels to force the country to become part of an EU customs union, a move that could threaten Theresa May's government.

The prime minister only holds power thanks to the support of Northern Ireland's DUP, and there is a serious threat her government could be brought down if a handful of her Conservative MPs team up with opposition parties to demand that she pursues some kind of post-Brexit customs union.

EU supporters back a form of union, which would align tariffs charged on goods imported from the rest of the world, saying it was essential in retaining tariff-free access to the continental market.

"The customs arrangements at the moment are hardwired into the membership treaty so I think everybody now recognises there's going to have to be a new treaty - it will do the work of the customs union," Starmer told BBC television.

"Obviously it's the only way of realistically to get tariff free access, it's really important for our manufacturing base."

He suggested that Labour could back an amendment by pro-EU Tory MP Anna Soubry to a trade bill currently going through parliament, demanding May "take all necessary steps" to secure a trade agreement that "enables the UK to participate after exit day in a customs union with the EU".

Brexiteers argue that such a deal would prevent Britain from striking free trade deals with the rest of the world, one of the key benefits of leaving the EU.