Britain and the EU are in a last-ditch effort to agree terms to keep trade flowing without tariffs or quotas from the start of 2021, after London's current standstill transition out of the 27-nation bloc ends.
"The outcome is uncertain. British overtures remain insufficient on the most sensitive matters," Jean-Yves Le Drian told a parliamentary hearing.
"At this time, Britain is dragging its feet on secondary matters and is playing with the calendar. I say this to our British friends, we won't let the calendar take priority over the content of the accord."
He said the two sides remained far apart on fishing rights, a totemic issue for both Britain and France. Britain, with rich fishing waters, favours annual catch negotiations but the EU is seeking a longer-term perspective for its fishing industry.
The other main sticking points are ensuring fair play for companies, including on state aid, and finding ways to settle future disputes.
"When we play football even away from home you have to play to the same rules and respect the rules. Otherwise it's another sport. You can't play cricket on a football pitch," Le Drian said.
Echoing comments made by European Commission president Ursula von der Leyen to the European Parliament on Wednesday, Le Drian said the EU was ready for all scenarios including a no-deal Brexit.
"It's up to the British to come out of tactical postures and make the necessary gestures. Sometimes it's better to have no deal than a bad deal," he said.
(Reporting by John Irish; Editing by Gareth Jones)
