Britain will publish further details of its Brexit negotiating strategy this week including a key paper on the European Court of Justice (ECJ) in an attempt to push talks towards a future trade relationship but amid a warning of delays.
Brexit Secretary David Davis has urged the European Union to discuss aspects of the future relationship now, arguing it is "inextricably linked" to some withdrawal issues that must be worked through first.
But Slovenian prime minister Miro Cerar suggested the issues in the first stage - a financial settlement, citizens' rights, and the Irish border - were too complex to solve in time to allow trade talks to begin in autumn, as hoped for by both sides.
Later this week, the Government is expected to publish a document on its plan to leave the "direct jurisdiction" of the ECJ.
But first there will be a paper which states the UK's wish to include services, as well as goods, in the first phase of talks, in a move apparently designed to inject pace into the process and take in some aspects of future trade.
Disagreement over the ECJ's role was a major sticking point during July's round of talks, with the UK aghast at Brussels' insistence that EU citizens' rights should be enforced by the court after Brexit.
This week's paper is expected to set out why the UK thinks direct ECJ jurisdiction should end and put forward different potential approaches to enforce rights after Brexit.
But it will come after a warning from Sir Paul Jenkins, formerly the Government's most senior legal official, that the UK will have to accept the ECJ in all but name if it wants to achieve a Brexit without hard borders.
It will also be published amid speculation that the Government could favour a mechanism modelled on the EFTA court, which adjudicates on issues relating to countries outside the EU that participate in the single market, such as Norway.
Addressing the issue at the weekend, Mr Davis said: "While we believe this will likely require a new and unique solution, our paper will examine a number of precedents."
Under the agreed timetable for negotiations, "sufficient progress" must be made on the withdrawal issues before talks on a future trade deal can begin.
Both sides hope that European Commission chief negotiator Michel Barnier will be in a position to make that recommendation to October's European Council summit of EU leaders, who will have to green light the opening of trade discussions.
Mr Davis originally predicted the "row of the summer" over the sequenced approach to talks but backed down.
Mr Cerar, who will be one of the 27 EU leaders at October's summit, told the Guardian: "I think that the process will definitely take more time than we expected at the start of the negotiations.
"There are so many difficult topics on the table, difficult issues there, that one cannot expect all those issues will be solved according to the schedule made in the first place."
Meanwhile, Crawford Falconer, the Government's new chief trade negotiation adviser, said the trade deals Britain could strike after Brexit would help boost global security.
Last week, the Government conceded the UK will not be able to implement any new free trade agreements under a proposed customs transition deal expected to expire around two years after Brexit in March 2019.
But Mr Crawford, who will work alongside International Trade Secretary Liam Fox from this week, wrote in the Daily Telegraph: "There is a powerful political and security element to getting this right.
"History is littered with instances of the destructive political consequences of closed markets.
"This was a lesson well understood at the end of the last century's global conflicts."
He added: "Many countries still recognise that open trade policies directed at engaging with others are at the core of any strategy to improve the global prospects for political openness and stability. They are already looking to partner with us to re-energise that agenda."
This week, the Government will also publish a paper on confidentiality which will make clear its intentions on ensuring official information exchanged between the UK, EU and other member states remain protected after Brexit.
A further document on civil judicial co-operation is designed to reassure the domestic legal sector.
And a paper on data will seek to ensure that it continues to be passed between the UK and EU without disruption.