The Labour party's divisions on Brexit will be laid bare today, as a group of up to 50 of its peers prepare to back an amendment on future membership of the EEA (European Economic Area).
The so-called Norway option has already been ruled out by the party's leadership, however Labours Waheed Alli will put forward amendments 110A and 112B this evening. Backed by Tory Baroness Verma and crossbencher Lord Bilimoria, the amendments are the upper house's latest efforts to force the UK to remain within the Single Market.
However the move is underscoring the splits within the party: Jeremy Corbyn has ordered his party to abstain, while shadow foreign secretary Emily Thornberry told the Today Programme "the truth is that that model will not fit the British economy".
She explained: "The Norwegian economy is very different from ours. We are the fifth largest economy in the world. We do need to have a British, bespoke deal. That does mean remaining close to the Single Market.
"In a way, we want to end up in the same place. It is just that the mechanism that is being put forward is simply one that technically we dont believe will work. And it is for that reason that we have differences with a lot of our colleagues, whom we have a great deal in common with. It is just that this particularly mechanism is not going to work."
The Tories are also struggling with their own Brexit divisions. In an interview with the Daily Mail, foreign secretary Boris Johnson slammed the Prime Minister's preferred customs option as "crazy".