A Labour MP has resigned, triggering a byelection in his Chester seat, after a report found he made “unwanted and unwelcome sexual advances” towards a junior member of staff. Parliament’s bullying and harassment watchdog, as well as the standards commissioner, found Chris Matheson had breached the sexual misconduct policy of the House of Commons. The independent expert panel (IEP) subsequently recommended his suspension from parliament for four weeks but Matheson said on Friday he had decided to stand down. It is understood Labour has also suspended Matheson’s Labour party membership as well as launching an investigation. The Labour chief whip is understood to have spoken to Matheson, 54, and told him he should stand down as an MP and advised him to stay away from the parliamentary estate. In a statement, Matheson said he felt the suspension of four weeks was an “excessive and unfair penalty” but he could not challenge it further and felt it was the “honorable and right thing to stand down”. He said the process had taken a toll on his health, including hospitalisation, and he was requesting privacy. Matheson also apologised to the people of Chester, the House of Commons for the “disrepute” he had caused, and to the complainant for causing hurt. However, he also disputed the findings of the reports, saying there were provable factual inaccuracies, and saying he had “no sexual motivation in this matter”. There were two main allegations upheld by parliament’s standards commissioner. In a report by the IEP, it said that in 2019 Matheson had invited the junior staff member to take a private trip to Gibraltar with him. The commissioner found that the invitation was sexually motivated, unwanted, and had placed the complainant under pressure and intimidated her. Secondly, it said Matheson took the junior staff member to a work-related dinner in January 2020 “and during the evening linked arms with her; made personal comments about her appearance while looking at her suggestively; made her hold his hand as they left and insisted on accompanying her to her bus stop; and once there invited her back to his flat, kissed her twice on the forehead and attempted to kiss her on the mouth”. The standards commissioner concluded that these were all unwanted and unwelcome sexual advances. A sub-panel of the Independent Complaints and Grievance Service also found that Matheson’s “continuing failure to acknowledge the full extent of his misconduct is an aggravating factor”. “It is insulting to the complainant. So too is his evidently false claim that he was acting only in a ‘fatherly’ or ‘friendly’ way towards her. In his excuses and denials, which he continues to persist in, he has sought to sow self-doubt and confusion in the mind of the complainant about his behaviour. That is quite unwarranted,” it said. Matheson has been the Labour MP for Chester since 2015. In 2017, he wrote on his website in a now-deleted post about the allegations of sexual assault and abuse against Harvey Weinstein that opened the floodgates for allegations in Westminster. “Some of the allegations involved tittle tattle about relationships between consenting adults. I believe they should have a right to privacy and can’t be conflated with sexual abuse, even though national newspapers try to do so in order to spread salacious gossip,” he wrote, while later adding that he hoped women would have the confidence to tolerate sexual harassment no more.