Seventeen French ministers and ex-ministers have vowed to "systematically denounce" sexual harassment, days after a probe was opened into multiple claims against a former deputy parliamentary speaker.

The signatories of Sunday's statement, who are all women, include the IMF chief Christine Lagarde,  former health minister Roselyne Bachelot and  former housing minister Cecile Duflot.

"We will no longer keep quiet," they said in a statement published by the Journal du Dimanche weekly newspaper.

They promised to "systematically denounce all sexist remarks, inappropriate gestures and inappropriate behaviour".

Their cross-party stand comes after French judges on Tuesday opened an investigation into multiple claims of sexual harassment against former deputy parliamentary speaker Denis Baupin.

Baupin, 53, vigorously denied the claims and has instructed his lawyers to sue two French media outlets for defamation, calling the allegations "mendacious".

The same day Finance Minister Michel Sapin became ensnared in a sexual harassment scandal after admitting that he acted "inappropriately" towards a female journalist after twice denying any improper conduct.

Sapin acknowledged late on Tuesday "making a comment" while placing his hand on the woman's back at a conference early last year - following two previous denials of a claim that he had tweaked her knicker elastic.

'Enough is enough'

The ex-ministers in their joint statement said that they had to either submit to or fight against sexism, like all women who have entered into previously exclusively male environments.

"It's not for women to adapt to these environments. It's the behaviour of certain men that needs to change," they said. "Enough is enough. Impunity is over."

The former ministers encouraged all victims of sexual harassment and aggression to speak up and lodge complaints.

"Today the judicial arsenal exists but the laws are not sufficiently applied".

They complained that labour laws protect employees but are not respected, with few women lodging complaints and very few of those complaints leading to convictions.

Source: AFP