Emmanuel Macron reacted furiously to Boris Johnson's claims that trade talks are "over" between the UK and EU. Mr Macron has played hardball in the talks on fisheries, insisting on Thursday that French fishermen would "not be sacrificed" for the sake of a deal.
However, if the UK leaves the EU without a deal then French fishermen could faced being banned from British waters.
In response, the French President has signalled the EU would launch a devastating energy embargo against the UK unless Boris Johnson gives in on fisheries.
Following the EU summit in Brussels on Friday, Mr Macron told French radio that if the UK does not allow French fishermen in its waters, the EU would have to block the UK's energy supplies to the European market.
He suggested the right to fish in British waters was worth 650 million euros to EU fishermen, but that access to European energy markets was worth up to £2.3billion (€2.5bn) to the UK.