Theresa May is chairing the first of two key Brexit meetings with her senior ministers as the government faces more calls to clarify the UK’s position.
The Brexit cabinet committee is to sketch out what the future relationship between the UK and EU might look like.
It is focusing on Northern Ireland and immigration, and on trade on Thursday.
It comes as a leaked document suggests the EU wants to be able to restrict UK access to the single market if there is a dispute after Brexit.
According to a draft section of the UK and EU’s withdrawal agreement, which has yet to be finalised, the power to suspend “certain benefits” would apply during a transition phase after the UK leaves in March 2019.
The UK said the document simply reflected the EU’s “stated directives”.
Speaking at Prime Minister’s Questions, Mrs May restated the government’s position that the UK would be leaving the single market and customs union and insisted she would be “robust” in getting the best deal.
“As I’ve said right from the very beginning, we will hear noises off, we will hear all sorts of things being said, of positions being taken,” she said.
“What matters is the positions that we take in the negotiations, as we sit down and negotiate the best deal. We’ve shown we can do that, we did it in December and we’re going to do it again.”
The tensions within the Conservative Party were underlined on Monday when pro-EU former minister Anna Soubry told the BBC Mrs May should “sling out” arch Brexiteers, and threatened to quit the party.
Eurosceptics have been calling for a “clean” separation with the EU so the UK has the freedom to strike new trade deals, while pro-EU MPs say the UK should retain the closest possible access to the single market.
Former Chancellor Ken Clarke said Theresa May had to see “where the majority of opinion” was within the cabinet, offer some concessions and those who could not live with the agreed stance would have to resign.
He told BBC Radio 4’s Today he wanted the UK to keep “most of the features of the customs union and the single market” after the transition period and suggested Parliament would back such a move.
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