The European Union's chief Brexit negotiator Michel Barnier has said that talks on the future EU-UK relationship are at a "moment of truth" and there remain only "a few useful hours" for a deal to take effect by Jan. 1. Barnier was addressing the European Parliament on Friday morning, as negotiators prepared to make a "last attempt", in his words, to break the deadlock. "We are at a moment of truth. We have very little time left, a few useful hours in this negotiation if we want this accord to come into effect on Jan. 1," the Frenchman told MEPs. "I cannot tell you what will be the outcome of this final push in the negotiation. That's why we must be ready for all scenarios," he added. EU lawmakers are due to vote on emergency measures in the event of "no deal". Negotiators would make a "last attempt to reach agreement particularly on fishing. We are not sure to get there if each side does not make a real and concrete effort", Barnier said. There are now under two weeks to go before the post-Brexit transition period expires on Dec. 31. Major changes resulting from the UK's departure from EU trading structures will be aggravated unless a deal on future ties is struck. Also speaking on Friday morning, Boris Johnson said "things are looking difficult" in terms of reaching a deal, adding that he hoped his "EU friends will see sense" in following the UK's example in working to bridge the gap in their positions. The British Prime Minister repeated that the UK wanted to control its own laws and borders, and also its own waters and fishing rights, and that "no sensible government" would sign up to a treaty that did not respect those "two basic things". On Thursday, European Commission President Ursula von der Leyen said "substantial progress" had been made in Brexit talks after a phone call with Johnson but admitted "big differences remain" and "bridging them will be very challenging". The two spoke early in the evening, their latest in a series of conversations in the past couple of weeks aimed at unclogging the talks which have moved at a snail's pace ever since the UK left the EU on Jan. 31. During the phone call, Johnson "underlined that the negotiations were now in a serious situation" and that "time was very short" to reach a deal, according to a Downing Street spokesperson. Hopes had risen over the past few days about the prospects of a breakthrough. However, everyone concerned knows that there really is very little time left for the remaining differences to be ironed out by Dec. 31 when the transition period formally ends. The European Parliament even issued a three-day ultimatum earlier to negotiators to strike a trade deal if they are to be in a position to ratify an agreement by the end of the year when the UK leaves the EU's tariff-free single market and customs union. European lawmakers said they would need to have the terms of any deal in front of them by late Sunday if they are to organize a special gathering before the end of the year. If a deal comes later, it could only be ratified in 2021, as the parliament wouldn't have enough time to debate the agreement before that. "We give until Sunday to Boris Johnson to make a decision," said Dacian Ciolos, president of the Renew Europe group in the European Parliament. "The uncertainty hanging over citizens and businesses as a result of U.K. choices becomes intolerable". One of the issues still proving an obstacle to an EU-UK trade deal is fishing rights, according to a statement posted on von der Leyen's Twitter account. "This evening I took stock with UK Prime Minister Boris Johnson of the on-going negotiations for a comprehensive Partnership Agreement between the European Union and the United Kingdom," it said. "We welcomed substantial progress on many issues. However, big differences remain to be bridged, in particular on fisheries. Bridging them will be very challenging". Following the call, the British premier said that a no-deal Brexit was "very likely" unless the EU's position shifted "substantially". He also said that the EU's stance on fisheries was "simply not reasonable". In a statement released by Downing Street following the call, a spokesperson said: "He [Johnson] said that we were making every effort to accommodate reasonable EU requests on the level playing field, but even though the gap had narrowed some fundamental areas remained difficult. "On fisheries he stressed that the UK could not accept a situation where it was the only sovereign country in the world not to be able to control access to its own waters for an extended period and to be faced with fisheries quotas which hugely disadvantaged its own industry. "The EU's position in this area was simply not reasonable and if there was to be an agreement it needed to shift significantly. An EU-UK trade deal would ensure there are no tariffs and quotas on trade in goods between the two sides, but there would still be technical costs, partly associated with customs checks and non-tariff barriers on services. As well as approval by MEPs, Britain's parliament must vote on any Brexit deal and the Christmas break adds to the timing complications. Lawmakers are due to be on Christmas break from Friday until Jan. 5, but the government has said they can be called back on 48 hours' notice to approve an agreement if one is struck. Though both sides would suffer economically from a failure to secure a trade deal, most economists think the British economy would take a greater hit, at least in the near-term, as it is relatively more reliant on trade with the EU than vice versa. Both sides have said they would try to mitigate the impact of a no-deal, but most experts think that whatever short-term measures are put in place, the disruptions to trade will be immense. "The prime minister repeated that little time was left," Downing Street said in its statement after the call. "He said that, if no agreement could be reached, the UK and the EU would part as friends, with the UK trading with the EU on Australian-style terms." Australia does not have a free trade deal with the EU. Failure to strike an agreement would see the EU and UK trade on basic international rules as part of the World Trade Organization (WTO). — Euronews