French President Emmanuel Macron has emerged weaker on the European stage after agreeing to yield to Ursula von der Leyen and sacrifice his heavyweight EU Commission nominee, Thierry Breton, experts say.

Breton abruptly quit on Monday with tough words for the EU's reelected executive chief von der Leyen, in an unexpected twist in the highly political power transition that follows June's European elections.

Although Macron's people say he has carved a more influential role for his replacement, Stephane Sejourne, a close Macron loyalist, it is becoming clear von der Leyen is the biggest winner of that swap, having won her fight with Macron.