Speaking at the start of a debate on the Queen's Speech on Monday, Boris Johnson repeated his promise to "get Brexit done" so his government could move on to other priorities. But while he was speaking, hopes of a deal in time for Thursday's European Council in Brussels were dimming.
"It's too early to say whether it's possible to get a breakthrough this week or whether it will move into next week," Tánaiste Simon Coveney said.
After Johnson's meeting last Thursday with Leo Varadkar, the negotiations in Brussels resumed with a focus on a new customs arrangement. Britain agreed that there should be no customs checks on the island of Ireland and the European Union accepted that Northern Ireland could leave its customs union with the rest of the UK.
For the European side, this meant that although the North would be part of the UK customs territory and would benefit from any new trade deals, it would be treated administratively as if it was still in the EU customs union.
Goods from Great Britain into Northern Ireland would be subject to customs checks and declarations and would be subject to the EU tariff. If the UK tariff was lower and the goods were not being moved beyond Northern Ireland, the importer could claim a rebate from the British government.
Alternative model
Britain favours a different model, which would create the equivalent of a green channel and a red channel at ports, with goods destined for Northern Ireland only passing through the green channel without checks and paying the UK tariff. Goods destined for the EU would go through the red channel and pay the EU tariff.
Over the weekend, EU negotiators raised a number of questions over the British proposal, most of which focused on the risk that goods moving through the green channel could end up in the European single market. Sugar imported into Northern Ireland by drinks or confectionary manufacturers, for example, could be used to produce drinks sold in EU countries.
British government sources say the talks are constructive and genuine but that the “nitty-gritty” details are proving slow to work out. The EU side warns that turning the British proposal into a legally operable plan and legal text could take weeks.
Johnson and his team have been in regular contact with the DUP throughout the process and are confident that the party remains on board for now. But they fear that adopting the EU's approach to customs without modification risks losing the party's 10 votes, and with them the support of some Conservative backbenchers.
The issue of consent could be an even greater challenge for the DUP, with signs that Johnson is moving away from the idea of a vote in the Northern Ireland Assembly to approve the plan in advance and renew that support every four years.
The prime minister must decide over the next 24 hours which is the greater risk to passing a deal through parliament: to move towards the EU’s position or to delay an agreement beyond this week.