France’s European commissioner, Thierry Breton, has resigned, citing “questionable governance” at the EU executive led by Ursula von der Leyen.

Breton, who was in charge of the EU’s single market and industrial policy, announced his immediate resignation in a post on X on Monday morning.

The French president, Emmanuel Macron, had appointed Breton to serve a second term as EU commissioner in June. But Breton said in his resignation letter that von der Leyen had asked Paris to withdraw his name “for personal reasons that in no instance you [von der Leyen] have discussed directly with me”.

“In light of these recent developments – further testimony to questionable governance – I have to conclude that I can no longer exercise my duties,” he added.

Breton announced his resignation with a touch of theatricality, by posting on X an empty frame hanging on a wall. “Breaking news: my official portrait for the next European Commission term,” he wrote, with his resignation letter following in a separate post.

The announcement adds to the disarray over the appointment of von der Leyen’s top team, which is already running late. In seeking a more gender-balanced lineup, von der Leyen inadvertently triggered a political row in Slovenia after putting pressure on the government to withdraw a male candidate.

She is expected to reveal details of the next commission, which has a five-year term, after meetings with senior MEPs on Tuesday. Her team consists of 27 EU commissioners, one from each member state, who will collectively be responsible for enforcing EU law spanning a swathe of areas including environment and climate, industrial and economic policy, foreign affairs, migration, farming and fishing.

Breton was one of von der Leyen’s most high-profile commissioners, who sparred with US technology companies such as X and Meta over regulations to curb the harmful effects of the internet, and oversaw moves to increase EU production of ammunition in light of the war in Ukraine.

The commission has not commented on Breton’s departure.

Rym Momtaz, the editor-in-chief of the Carnegie Europe thinktank’s Strategic Europe publication, wrote: “There’s never been any love lost between von der Leyen and Breton, but this EU commission composition is like a Succession/Game of Thrones mashup.”

A former business executive, Breton was not afraid to criticise his boss. He joined other senior colleagues last year in criticising von der Leyen’s decision to appoint a fellow German member of the Christian Democratic Union party to a senior role he was said to be less qualified for than others.

When von der Leyen was running for re-election this year, Breton questioned whether she should get a second term. “Is it possible to (re)entrust the management of Europe to the EPP for five more years?” he wrote on X after the centre-right European People’s party alliance gave von der Leyen an underwhelming majority when selecting her as their candidate. “The EPP itself does not seem to believe in its candidate,” he wrote.

Von der Leyen, who was reappointed by EU leaders and re-elected by the European parliament to serve a second term, has long faced accusations that she is aloof, lacks transparency and fails to involve senior colleagues in EU decision making.

Supporters point to her record of support for Ukraine and creation of a post-Covid recovery fund, but Breton’s letter is likely to add to criticism about her working methods.