France is in the midst of two of its favorite pastimes: political turmoil and fashion week -- two worlds that increasingly collide. 

Fashion writer Marc Beauge, who has advised at least one president, walked AFP through the evolving style rules for French politicians.

For male politicians, he said, a simple uniform has become dominant: a navy blue suit -- fitted and generally a little too slim -- with a white shirt and thin tie.

"It signals respectability, authority, and above all a lack of ostentation. It's middling quality and can't be accused of elegance," said Beauge.

This is particularly popular among centrists and social democrats, and is the go-to look for President Emmanuel Macron, even though practically no one in France wears such outfits in the street or office anymore -- least of all the start-up crowd Macron favors.

The president has changed styles since calling the snap election last week, however -- to funereal black suits. 

"There's no more blue and grey," said Beauge. "It's a way of showing the gravity of the moment."

Women politicians have largely abandoned the neat designer outfits of the past in a bid to look less elitist.

"It's always the same trouser-and-jacket combos that ensure no sexist commentary, but which risk making them invisible," said Beauge.

Socialist Segolene Royale, once known for her preppy Chanel tweeds, headbands, and knee-length skirts, went decidedly more demure by the time she was running for the presidency in 2017.

When Bauge was summoned to the Elysee Palace by then-president Francois Hollande for style advice in 2014, his instruction was "neither too chic nor too redneck".

Once popular with presidents, Rolex watches have been dumped.

All remember the spectacular gaffe by a close advisor to then-president Nicolas Sarkozy in 2009, who said, in the midst of an economic crisis: "If you don't have a Rolex by the time you're 50, then you've clearly failed in life."

Extreme style

While the centrists seek neutrality, the political extremes are always making clear statements, said Beauge. 

Far-right leader Marine Le Pen, whose National Rally (RN) has been surging in polls, ordered her deputies to wear sharp suits and ties after the last legislative elections in 2022.

It was part of a strategy to make the party seem a natural part of French institutions rather than a radical fringe.

"The idea is that RN deputies must be better dressed than the average French person," Beauge said. 

Meanwhile, far-left leader Jean-Luc Melenchon rarely strays from his short-collared worker's jacket -- a classic Communist symbol.

Many left-wing deputies seek to signal they are not part of the political elite with jeans, jackets and few ties, said Beauge. 

This led one right-wing leader, Renaud Muselier, to accuse them of being "dirty and dishevelled", triggering an ironic protest in which women deputies showed up wearing them over dresses and jeans.