Prime Minister Boris Johnson is "optimistic" about striking a post-Brexit deal with the European Union but ready for Britain to trade on new terms without one, aides said on Wednesday.
"He is optimistic but he's also always said that he is confident and comfortable that we would be OK without a deal," Johnson's press secretary Allegra Stratton told reporters.
"If a deal can be struck that's all to the good, but he's also confident that we can move towards trading on what he calls Australia terms," she said, referring to Johnson's formulation for trading under World Trade Organization terms.
With intensive talks in London going down to the wire, the Downing Street comments came as chief EU Brexit negotiator Michel Barnier warned he could not guarantee a deal with Britain and that the next few days will be crucial.
Differences remain over regulatory issues, governance of a future pact, and fisheries, Barnier was quoted as saying by EU diplomats as the clock ticks to the end of a post-Brexit transition period on December 31.
"We remain engaged in intensive talks. We want to reach an FTA (free trade agreement)," Johnson's official spokesman added on the briefing alongside Stratton.
He refused to comment on details of the talks, but stressed British demands for the EU to "fully respect UK sovereignty".
"That's not just a word. It has practical consequences," he said, pointing to Britain's desire to regain full control of its borders, state aid policy, and fishing waters.
Another threat looms to the talks if Britain carries through with plans to revoke parts of its EU withdrawal treaty in two pieces of legislation -- an internal market bill, and a forthcoming finance bill.
Johnson's official spokesman reiterated that treaty-violating clauses designed to keep Northern Ireland trading freely with Britain were merely a "legal safety net".
Stratton denied that failure to strike agreement, and possibly shunt the negotiations into next year after a chaotic no-deal break, would poison relations with Brussels.
"We have perfectly civil and indeed warm relations with our European friends and colleagues," she said.
"We have a negotiating team right now working really hard to get a deal.
"And until it's clear that they have or haven't, that's not something that anybody in this building is thinking about, how are we going to deal with the EU if we don't get that deal."