A senior Scottish National party MP accused of sexual assault has quit the party and will sit as an independent after the Metropolitan police said they were investigating the allegations. The Met said it had received a complaint from a third party about Patrick Grady’s alleged sexual assault of a 19-year-old party worker at the Water Poet pub on Folgate Street, London, in October 2016. A former chief whip, Grady was suspended from the Commons for two days on 14 June after an independent panel upheld the worker’s accusations that the MP made an unwanted sexual advance. Grady, who has apologised, was found by the panel to have touched and stroked the then teenager’s neck, hair and back. The MP was also suspended by the SNP for a week, triggering widespread criticism of party leaders for appearing to downplay the severity of Grady’s conduct and failing to take faster action against him. The party worker first complained informally in 2018. The controversy deepened after a recording emerged of Ian Blackford, the SNP’s Westminster leader, which appeared to show the party’s Westminster group siding with Grady. To apparent applause from other SNP MPs, Blackford urged Grady’s colleagues to rally around him by “giving him as much support as possible”. The victim of the alleged assault, who has not been named, was furious and accused the party of failing to uphold its public claims it had zero tolerance of sexual misconduct. He said its officials had instead sidelined and bullied him since he made the complaint. During a bruising session of first minister’s questions last week, Nicola Sturgeon, the first minister and SNP leader, was accused by opposition leaders of presiding over repeated failures to support the employee and of significant inconsistencies in the party’s handling of misconduct cases involving its MPs and MSPs. In a statement on Sunday, the Met said: “On Wednesday 22 June police received an allegation of sexual assault that is said to have taken place in October 2016 at a commercial premises in Folgate Street, E1. “The report was submitted online by a third party. Officers will now be making inquiries, including contacting the alleged victim, in order to assess what further action is required.” An SNP spokesperson said: “Patrick Grady is stepping away from his party membership while the police inquiry continues.” It remains unclear whether he volunteered to stand aside. The Sunday Mail said the police complaint was made by another employee at the House of Commons. The Sunday Times reported that Grady was now coming under pressure to quit as MP for Glasgow North before the next general election, to avoid losing the seat to Labour. He won the seat in 2019 with a 5,601-vote majority. Blackford announced an external review of the Westminster group’s actions as he sought to quell mounting unrest. The SNP is also rushing new rules through its national executive committee for handling internal harassment complaints, with party activists planning to table motions to SNP conference calling for clearer sanctions against perpetrators.