The European Union has challenged the UK to return to the table and discuss trade negotiations, as the bloc's negotiator says a deal with London remains "within reach."

Both sides remain deadlocked over issues including access to fisheries and state aid rules, and they have just over a week before the UK-imposed October 31 deadline to agree on a deal or risk further adding to the economic pain caused by the coronavirus crisis. 

"Time is very short and we stand ready to negotiate 24/7, on all subjects, on legal texts. The UK has a bit of a decision to make and it's their free and sovereign choice," European Council President Charles Michel told the European Parliament.

Michel said the UK's answer would determine its level of access to the EU's internal market of 450 million consumers.

The EU's chief Brexit negotiator Michel Barnier struck an optimistic tone, telling the parliament an agreement was still "within reach."

"Time is of the essence ... Along with our British counterparts, we must find solutions to the most difficult areas," Barnier said. His comments pushed sterling higher in the currency markets. 

In turn, London has refused to continue full negotiations, saying the EU must "fundamentally change" its stance if talks are to resume.

A UK spokesman said London noted "with interest" Barnier's comments that touch "in a significant way on the issues behind the current difficulties in our talks." While Barnier and his UK counterpart David Frost were due to talk on the phone later on Wednesday.

Michel stressed that the 27 EU members were ready for an abrupt split from the UK without a new agreement to avoid tariffs or quotas. 

He listed three main sticking points in the negotiations: guaranteeing fishing rights, ensuring economic fair play and agreeing on ways to settle future trade disputes.

"We don't need words, we need guarantees," he said of fair competition safeguards. "Do our British friends want to regulate state aid and uphold high medical standards? If so, why not commit to them."