Brexit trade talks are in the "final last chance saloon" this week, the environment secretary has said, with fisheries and state aid still the major points of disagreement between the UK and EU.
George Eustice told ITV News he is "optimistic" that a deal can be reached, despite intense talks over the weekend ending without an agreement.
But he said "some difficult obstacles remain, in particular the EU's current insistence that they want the same access rights that they currently enjoy under the fisheries policy - we can't obviously accept that".
He added: "A deal can be done, a deal can be reached, but we really are in the final, last chance saloon if we are to bring one to a head."
The EU's chief negotiator, Michel Barnier, when asked if negotiators had got any closer to reaching an agreement on fishing rights, he simply replied "poisson" - the French term for fish.
He did not answer questions about whether a deal would be reached in time for the UK's exit from the bloc at the end of the year.
Mr Barnier and his UK counterpart Lord (David) Frost were holding in-person talks in central London this weekend.
The two sides are locked in talks over how much access the EU will get to UK waters and the fish that are caught in them.
Mr Eustice said the EU "will need to change position if we are to get to an agreement".
Mr Raab stressed there is a deal to be done, however, and added this could be the last week of “substantive” negotiations.
Speaking on Sky's Sophy Ridge on Sunday, he urged Brussels to recognise the “point of principle” on Britain’s control of its waters.
“I do think we’re in a reasonable position – there’s a deal to be done," he said.
“If you look really at what the outstanding issues are, of course the level playing field, but it feels like there is progress towards greater respect for what the UK position was.
“On fishing there’s a point of principle: as we leave the EU we’re going to be an independent… coastal state and we’ve got to be able to control our waters.”
As Brexit talks continued over the weekend, Britain demanded the European Union brings “fresh thinking” to trade deal talks.
The UK has also called on the EU to concede on fishing rights ahead of what Downing Street said could be the last week of negotiations.
Fishing rights remain an “outstanding major bone of contention” in post-Brexit trade talks with the EU but there is a deal to be done, Foreign Secretary Dominic Raab has said.
The EU’s chief negotiator Michel Barnier has been in London for talks this weekend, with his UK counterpart Lord (David) Frost.
Arriving at the talks on Sunday morning, Mr Barnier told reporters: “Work continues, even on a Sunday.”
But Downing Street warned there remains a lot to do at a late hour.
Progress is understood to have been made across many areas, yet significant gaps are said to remain on the EU’s access to UK fishing waters when the transition period ends on December 31.
Reports last week suggested that Mr Barnier recently said the EU could accept a 15-18% cut in its share of fishing rights in UK waters, but British officials were said to have immediately rejected the offer.
A government source said: “These figures are risible, and the EU side know full well that we would never accept this.
“There seems to be a failure from the Commission to internalise the scale of change needed as we become an independent nation.”
The government has repeatedly said it is prepared to leave the transition period without a deal if the EU fails to move, and talks have been deadlocked for months over fishing rights and other issues.
They include the governance of any deal and the “level playing field” conditions aimed at preventing unfair competition by cutting standards or increasing state subsidies.
But ahead of what Number 10 said could be the final week of talks, a source close to the negotiations said: “Over the coming days we will continue to negotiate with creativity and intensity.
“We hope that the EU will come with some fresh thinking because what we’ve seen so far doesn’t cut it. They must understand that we are not going to sell out our sovereignty.”
Mr Barnier arrived in London on Friday night telling reporters that he would continue to work with “patience and determination” to reach an agreement.
Face-to-face negotiations were paused earlier this month after one of the EU team tested positive for coronavirus, but in-person discussions resumed on Saturday morning.