The EU official said the bloc has “never been impressed” by threats of the UK crashing out on October 31 without agreeing a deal.
Asked what would happen if the UK "just tore up the membership card" for the EU, he said: "The UK will have to face the consequences."
"I think that the UK side, which is well informed and competent and knows the way we work on the EU side, knew from the very beginning that we've never been impressed by such a threat," he added.
Mr Barnier’s comments came as the House of Commons was set for a showdown over moves to prevent a no-deal Brexit.
MPs will have the chance to vote on legislation that could potentially thwart efforts by the next prime minister to try to suspend Parliament to force through EU withdrawal without an agreement on October 31.
The clash is looming because the Lords strongly backed a bid to block Parliament being suspended in order to facilitate a no-deal exit by a margin of 103 votes on Wednesday.
The Office for Budget Responsibility is also expected to announce that a no-deal Brexit would force Britain into a recession, shrinking the economy by three per cent next year, according to The Times.
The economic forecaster will give its first assessment of a no-deal Brexit, predicting its impact on household incomes, employment and house prices.
Elsewhere in the BBC Panorama programme, which will be broadcast on Thursday night, the EU Commission’s First Vice-President Frans Timmermans said it was “shocking” how unprepared the UK’s negotiating team had been when they arrived in 2017.
He compared them to Lance Corporal Jones from Dad’s Army and said ministers were “running around like idiots”.
Meanwhile Thursday's vote in the Commons could see further amendments by anti-no-deal MPs selected by the Speaker, John Bercow.
The move comes amid reports that some ministers could resign in order to back efforts to block no-deal if a free vote on the issue is not offered by Prime Minister Theresa May.
Front runner for the Tory leadership Boris Johnson again refused at the final campaign hustings on Wednesday to rule out suspending Parliament in order to meet his red line of getting the UK out of the EU by Halloween.
Rival for Number 10 Jeremy Hunt has insisted he would not use such a constitutional manoeuvre to force EU withdrawal.
The amendment to the Northern Ireland (Executive Formation) Bill builds on an amendment passed in the Commons last week, when MPs backed a proposal from the pro-European Tory Dominic Grieve calling for fortnightly reports from the Government on the efforts to restore the power-sharing executive.
The new Lords amendment would ensure these have to be debated in the weeks before the Brexit deadline.
The Bill could theoretically make it illegal for the Government to prorogue parliament in the autumn if the power-sharing executive in Northern Ireland has not been restored.