Negotiations on the significant relationship between the UK and the EU have “drained to wires”, with fisheries and youth mobility in outstanding points in advance of the pivotal summit.

In a scenario reminiscent of the Brexit talks, British officials are still trying to reach a compromise with their EU counterparts as Keir Starmer prepares to host European Commission President Ursula von der Leyen in London on Monday.

EU ambassadors discussed the summit at an unusual Sunday meeting in Brussels, where they were told to hold further meetings in the evening or early Monday as the deal was not yet completed.

"The negotiations boil down to wires, and a deal has not been reached. Both sides have some outstanding issues and the dialogue will continue overnight," said the British government source.

No 10’s decision to issue a press statement on Saturday to use the summit as a closing deal sparked stimulus from Brussels, prompting some to recall the mantra of the Brexit negotiations: “No consensus was reached until everything was agreed.”

"The whole discussion is a plan. We will not accept only the case of the UK's advantages (or) requirements without strong assurances and commitments to other important issues in the EU, such as fisheries, energy, youth mobility."

British Minister Nick Thomas-Symonds, who is in charge of the negotiations, said on Sunday that the negotiations were at the "last time" but admitted that key details of the deal are still being formulated.

However, the flagship security and defence partnership means the UK will receive a £125 million EU defence fund to re-raise the mainland, highlighting the intimacy of security relations with Ukraine, which may be the driving force behind British defence companies.

Downing Street hopes the summit with von der Leyen and other Brussels chiefs will draw a line in the turbulent Brexit era and show that Britain has changed. They believe the deal will be seen as a "step" to build a deeper partnership with Europe.

Ministers are ready to take a major political offensive to explain the benefits of closer ties to the EU, and there is some anxiety about how Britain’s reforms are being responded to in labor.

Conservative leaders Nigel Farage and Kemi Badenoch have both described the deal as "surrender", although details are not known yet and said they will tear it down if they come to power.

Starmer is also facing pressure from both the workforce and the progressive side to further develop. Liberal Democratic leader Ed Davey urged the prime minister to “be bold and ambitious about our country” while ignoring “fighting the old battles.”

There has been a significant change in the public's attitude towards Brexit. Polls now show that two-thirds of British people have established closer ties with the EU, with only 20% opposed it.

Fishing is still a stumbling block to the deal going online. The EU insists that the UK government can reach British waters for a long time, beyond the four-year agreement proposed by the Stamer administration, but rather pushing for double-digit expansion.

Brussels has contacted fishing with agreements to sell sales of food, animals and other agricultural products called sanitary and phytosanitary goods. The EU recommends fixing it within the same time frame as fish.

It is also understood that the two sides are discussing the language of a youth mobility agreement that allows young people aged 18 to 30 to travel more easily between the UK and the group, which is the EU's focus on digital quotas.

British ministers talked about a "smart and controlled" plan, which suggests it will have a cap and time limit and operate in accordance with actions from the UK's 13 deals with countries including Australia and Canada. Conservatives suggest it will involve a free movement of “backdoors.”

Other issues that are understood to be left on the table on Sunday night are tuition fees, Brussels pushes EU students in the UK to pay domestic interest rates instead of international tax rates, rather than higher international tax rates, and the fees for EU nationals to use the NHS.

However, British holidaymakers are expected to face shorter airport queues this summer. Negotiators are about to reach an agreement to provide UK passport holders with electronic gates in Europe instead of waiting for queue stamps.

With plans to merge the UK and Europe emissions trade plans, the government said it would reduce household bills and open electricity transactions with the mainland.

Starmer faces political struggles with Britain's reforms and the Conservatives in his deal. Badenoch has promised that if she takes office, she will remove any Starmer that crosses the strict Brexit line. Her commitments didn't help, and he tried to convince Brussels that Britain was now a reliable negotiating partner.

Meanwhile, Lib Dems urged the government to join the new UK EU Customs Alliance to grow through the group and grow trade. David said: "The Prime Minister must ignore the dinosaurs fighting the old battles, they want to drag us back to the destructive Brexit war in the past and focus on getting the biggest deal for Britain."

The SNP further argued that there was no better deal than rejoining the EU, nearly a decade after the UK voted to leave. Its European spokesman Stephen Gethins added: "This is the biggest and best growth strategy, but it's the only option for Labour because they're afraid of Nigel Farage."