Last Friday, the EU and Britain blamed each other for the lack of progress after the latest round of post-Brexit trade talks.
The EU said a deal seemed unlikely.
Barnier issued his warning at the end of the seventh round of trade negotiations.
This cycle included key issues such as fishing rights and competition rules.
Brexiteer Ben Habib said Michel Barnier was overconfident in Brexit trade negotiations.
Former Brexit MEP Ben Habib recently said the UK must prove to the EU that it intends to leave the bloc without a trade deal.
Speaking to Michael Heaver about Westminster, Mr Habib said Michel Barnier was acting as if the EU had blamed the UK.
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“The best way to convince them is to just leave. “
He added: “I suspect Boris Johnson doesn’t believe in a no-deal Brexit, despite all his support and bravado.
“You might remember that last year or so they said we would be out by October 31 with or without a deal.
“But actually, I don’t think they believe in any deal.
“Michael Gove, who is in charge of no-deal planning, has publicly stated that he does not believe in no deal and that he thinks it will be bad for the UK.