When the French fleet could have joined Britain in 1940

When could the French Navy have joined Britain during the fall of France?

Before France surrendered, French ships could have sailed out and joined the Royal Navy, which would have accepted them.

French warships could have departed before France surrendered and joined British forces. The Royal Navy would have accepted them. The practical window depended on French commanders and crews moving while they were still free to choose that course. The panel therefore sees several possible routes to cooperation before the surrender rather than a single later transfer point.