A former French senator has been found guilty of spiking an MP’s drink with ecstasy in order to sexually assault her.

Joel Guerriau received a four-year prison sentence – 18 months of which are to be served behind bars – and, according to local media, was ordered to pay Sandrine Josso €5,000 (£4,348) in damages for emotional distress.

Guerriau, now 68, had invited Josso, 50, to his Paris flat in November 2023. He later admitted serving her a drink spiked with MDMA, but maintained it was an accident and denied having any intention of assaulting her.

Shortly after the verdict on Tuesday, Josso said it was a “huge relief”, AFP reports. Meanwhile, Guerriau’s lawyers said he would appeal.

According to court documents quoted by French media, Josso said she had gone to Guerrieau’s home three years ago to celebrate his re-election when she started feeling unwell after drinking from a champagne glass.

“I had gone to visit a friend and I discovered an aggressor,” she said on Monday while giving evidence in the trial.

“He looked at me insistently, I’d never seen him that way. I didn’t want to show him my weakness, because I was worried that if I told him I wasn’t feeling well, he would’ve forced me to lie down.”

Josso recalled managing to leave the flat and, with the help of a colleague, went to hospital where a toxicology report confirmed her blood had three times the recreational dose of MDMA.

Guerriau told the court he had been going through a period of depression, and had meant to take the drug himself the night before. He did not end up doing so and accidentally offered the glass containing MDMA to Josso the following evening, he said.

“I feel sorry for Sandrine,” Guerriau told the court in Paris. “I am disgusted with myself, with my recklessness and my stupidity.”

He added: “We don’t talk about the effects of these drugs enough… All I want is to speak out on the dangers of these products.”

Asked about the several internet searches he made around ecstasy and the drug GHB, he said he had no recollection.

“I was on the train, thoughts and ideas just come to you,” he told the court, adding government members needed to show an interest in “all current events”.

Guerriau, a centre-right senator from the Horizons party, was suspended when the charges against him came to light. He resigned as a senator last October.

Josso, who is still an MP for the centre-right MoDem, has become a staunch campaigner against so-called chemical submission – drug-facilitated sexual assault.

“What I went through is still very painful,” Josso said, speaking to French media ahead of the trial beginning.

“Psychological trauma feels like being frozen in time… I jump at the slightest thing. I’ve become very vulnerable.”

Josso has gone on to join an association against chemical submission, set up by Caroline Darian – the daughter of Dominique Pelicot, who in 2024 was found guilty of drugging his wife Gisele and inviting men to rape her in their home for over a decade.

Josso was often in court during the Pelicot trial. This week, Darian and her brother David attended the proceedings in the Guerriau case.