Shadow Brexit secretary Keir Starmer said this morning that the UK must stay in a customs union with the EU, and that it should not attempt to negotiate independent trade deals.
Providing an update on Labour's policy on Brexit, Starmer said "the benefits of the customs union must be retained" after March 2019.
Speaking on the Andrew Marr show, he said: "There is going to have to be a new customs union...There is going to have to be a new agreement."
Starmer said the UK would be better off negotiating new trade deals alongside the EU, and that "the cost/benefit analysis is absolutely clear on this". He challenged Liam Fox to come up with some credible analysis supporting his plan for the UK to negotiate its own trade deals, and set an independent trade policy.
Tomorrow, Labour leader Jeremy Corbyn will give a speech on Brexit which will outline the party's position. The party has been accused of failing to clarify its stance, and many Labour MPs have been trying to make their leader commit to Single Market membership.
In a letter to the Observer today, 80 senior Labour figures have argued that Corbyn will be unable to support his planned investments into public services unless he keeps the UK in the Single Market.