Valerie Trierweiler, the French first lady, has caused a storm in her country – and managed to upset the mother of her partner's four children – with a single tweet.
French President François Hollande is facing backlash after Valerie tweeted her support of a rival of his ex, Segolene Royal, in parliamentary elections.
Segolene was Mr Hollande's partner for 30 years until he left her in 2007 to be with Paris Match journalist Valerie.
The 58-year-old member of the French Socialist Party, who stood for the presidency in 2007, is in the running for a parliamentary seat in the western constituency of La Rochelle.
She gained 32 per cent of the vote in the first round of elections on Sunday, and hopes to win during the second round the following week.
Her opponent is fellow left-wing socialist Olivier Falorni, who refused to back down and support her, garnering 29 per cent of the vote in the first round.
As expected, Mr Hollande expressed his support for his ex, saying: "Segolene Royal is the only candidate of the presidential majority who can be assured of my support."
But shockwaves were sent through the Socialist Party when Valerie responded by tweeting her support for Segolene's rival.
"Good luck to Olivier Falorni who was not unworthy, who fights alongside the people of La Rochelle for so many years with selfless commitment."
Commentators have said such a text from the president's wife could sway the vote towards Mr Falorni, ruining Segolene's chances.
Valerie is said to be unhappy that her partner has got involved in the election battle, after he gave his backing to his ex.
A commentator close to her told the Daily Telegraph the 47-year-old had acted out of "blind jealousy".
Mr Hollande's political opponents have criticised the turn of events.
"As of this morning, 'normal' presidency is well and truly dead. From now on it's Dallas at the Elysée," said Geoffrey Didier, the centre-right UMP's national secretary.