Denis Baupin, who did not surrender his seat as an elected member of the lower house of parliament, rejected the accusations in a statement published on his website.
“Following the accusations in the media, Mr Denis Baupin wants to stress … that these are defamatory and baseless lies,” the statement said, adding he had resigned to protect the reputation of parliament and to defend himself.
Baupin is the husband of Housing Minister Emmanuelle Cosse. He recently left the pro-environment Greens party over disagreements about strategy.
He came under sudden pressure to resign after female party officials and lawmakers went on the record on Monday in French media to level accusations at him.
Sandrine Rousseau, a Green party spokeswoman, told France Inter radio and Mediapart online media, which first revealed the case, that one day in October 2011, “he pressed me against the wall, holding my breasts and tried to kiss me.”
Lawmaker Isabelle Attard said: “It was an almost daily harassment with provocative, salacious text messages.”
In France, accusations of sexual harassment by politicians rarely come out in the open.
In May last year, a group of female political reporters published an article in which they denounced inappropriate comments and harassment they had to deal with in their work. They gave examples but did not expose politicians by name.
They said at the time that they had hoped things would have changed after the worldwide attention sparked by the arrest of Frenchman Dominique Strauss-Kahn on sex offence charges in 2011.
Strauss-Kahn, who was widely tipped to become France’s next president, quit as head of the International Monetary Fund after his...