French First Lady swipes at president's ex Valerie Trierweiler, companion of French President Francois Hollande, talks to pupils in a ...

French First Lady swipes at president's ex

Valerie Trierweiler, companion of French President Francois Hollande, talks to pupils in a classroom during her visit at the French School in Chicago, May 21, 2012. REUTERS/Eric Feferberg/Pool

France's First Lady set the country's Twitter network alight on Tuesday with a good luck message to the parliamentary election rival of Segolene Royal, the Socialist politician who used to live with her partner President Francois Hollande.

The message from Valerie Trierweiler entertained opponents of Hollande's Socialists and added a shot of venom days ahead of the June 17 ballot for the lower house of parliament, the National Assembly.

In her post on the messaging network, Trierweiler told Olivier Falorni - a left-winger who has defied Socialist Party orders to step aside in favour of Royal in a constituency in western France - to "Take heart".

The tweet praised Falorni, saying he had spent years working with the people of the constituency where he is running, the western seaside town of La Rochelle.

Royal, mother of Hollande's four children, declined to comment on what local media called a "bombshell" from Trierweiler, but others jumped to her defense.

Prime Minister Jean-Marc Ayrault and Socialist Party chief Martine Aubry both said Royal's election bid had Hollande's unequivocal support. "That's what matters," Ayrault added.

Hollande's Socialist Party ditched Falorni earlier this year over his refusal to pull out of the contest. Royal could be blocked from holding a frontline political post if she fails to win the National Assembly seat.

Far-right leader Marine Le Pen, who also hopes to win a seat in parliament, said: "Madame Trierweiler is settling scores with the ex of her partner, who happens to be the president - how pitiful."

Dominique Bussereau, a former minister from the centre-right UMP party, called Trierweiler's swipe "kind of enjoyable and refreshing".

Royal ran unsuccessfully for president herself in 2007, the year she announced she and Hollande were splitting after a quarter of a century together.

Last year, she cried after being knocked out early in the Socialist primary for this year's presidential election that Hollande went on to win on May 6.

Trierweiler, 47, a twice-divorced journalist, has been living with Hollande for several years, after she grew close to him toward the end of his relationship with Royal.

Hollande, 57, never married Royal and has not indicated he will marry Trierweiler to formalize her role as First Lady.

He offered no comment on an issue that officials close to the new president described as a "slip-up" or "hiccup".

Trierweiler did not respond to a request from Reuters for more information on her message.

Falorni, who came second to Royal in a first-round vote and hopes to beat her in next Sunday's runoff, did respond to the tweet though, saying on television: "This is a sweet surprise for me."