If there is no “substantial shift” from Brussels in the coming days, no post-Brexit trade deal between the UK and EU will be reached, a government source has said, BBC reported on Saturday.

As reports suggest there is likely to be a decision before Christmas on whether or not a deal can be reached.

An EU source said it was “in both sides’ interest to reach a fair deal,” however, it remains to be seen how long the arrangements take.

The UK government sources say it is increasingly likely the country will end its post-Brexit transition period without a free trade agreement with the EU, the public broadcaster wrote.

This could see tariffs introduced on goods being sold and bought – which may lead to increased prices for certain products.

A government source told the BBC: “We need to get any deal right and based on terms which respect what the British people voted for.

“Unfortunately, the EU are still struggling to get the flexibility needed from member states and are continuing to make demands that are incompatible with our independence.

“We cannot accept a deal that doesn’t leave us in control of our own laws or waters.

“We’re continuing to try every possible path to an agreement, but without a substantial shift from the [European] Commission we will be leaving on World Trade Organization terms on 31 December.”

Prime Minister Boris Johnson has pledged to keep talking but warned gaps had yet to be bridged.

Senior MEPs in the European Parliament have said they will not be “rushed” into signing off a deal on their side and want to see the text of any agreement by Sunday if they are to approve it by the end of the year.

Speaking in the European Parliament on Friday, the EU’s chief negotiator, Michel Barnier, said, BBC reported, that while there was still a “chance” of a deal, the “path was very narrow”.

A senior EU source told the BBC’s Brussels correspondent Nick Beake: “The Member States are the EU. And as a former member state, the UK knows well that the EU negotiator is there to protect the interest of Europeans.

“We believe it is in both sides’ interest to reach a fair deal, which cannot be the case without a level playing field and sustainable arrangements for fisheries.”

The two sides have been at odds over the length of time it will take to introduce new arrangements once the UK leaves the bloc’s Common Fisheries Policy.

The UK, led by its chief negotiator, David Frost, has insisted its sovereign rights over its waters must be respected from day one and its fleets must be able to keep a much larger share of their own catch.

The two sides are reported to have made progress in recent days on the issues of fair competition and what to do if the UK is deemed to get an unfair competitive advantage by moving away from EU rules and standards.