THE SNP has been urged to block Patrick Grady’s return to the party after the Metropolitan Police dropped their probe into allegations of sexual harassment. 

Lib Dem chief whip, Wendy Chamberlain - a former Detective Constable with Lothian and Borders police - said that the lack of a criminal investigation into the disgraced MP "does not mean that what he did was ok."

She also described Ian Blackford as a "moral vacuum" and called on him to resign as the SNP's Westminster leader.

The Met launched its investigation last week after a complaint from a party staff member. 

At the time, the SNP said the Glasgow MP was “stepping away” from his membership while police carried out their inquiries. 

However, the probe lasted little more than a week, with the Met saying no further action would be taken.

It is not yet clear if Mr Grady will apply to rejoin the SNP. It is also not clear if the party would accept his application. 

The Glasgow North MP was suspended from Parliament for two days after he was found to have “made an unwanted sexual advance” while “under the influence of alcohol” to an SNP member of staff 17 years his junior.

Mr Grady, the party's former chief whip, told the Commons he was "profoundly sorry" for touching and stroking the neck, hair and back of the then 19-year-old colleague during a social event at a London pub in 2016.

The row over his conduct escalated dramatically after a recording of the SNP Westminster group’s meeting after the finding was leaked to the media.

Despite group leader Ian Blackford promising a "zero tolerance" approach to harassment in 2017, he was heard urging his fellow MPs to give Mr Grady their "full support", leading to cries of "hear hear".

Nicola Sturgeon called the contents of the recording "utterly unacceptable" and apologised for the victim feeling unsupported. 

Mr Blackford has since turned on Mr Grady, saying he should reflect on his conduct and position, and said his future is now a question for his constituency party.

Liberal Democrat chief whip Wendy Chamberlain said the whole row had left the SNP unable to comment on the allegations surrounding Tory MP Chris Pincher, who faces multiple allegations of inappropriate behaviour. 

While Labour and the Lib Dems have released statements calling on Boris Johnson to explain what he knew about the accusations, the SNP has remained unusually quiet. 

Ms Chamberlain -a former detective - said: “The SNP have been forced into allowing allegations of sexual misconduct within the Conservative party to pass without comment because they know they have failed at dealing with their own complaints.

“Just because the police have said they will not be conducting a criminal investigation into Patrick Grady does not mean that what he did was ok. Ian Blackford has been exposed as a moral vacuum, more concerned with protecting his friends than ensuring a young staff member got justice.

“Handling these types of allegations is something that all parties need to do better on. For the SNP, that should start with refusing to hand back the party whip to Patrick Grady and removing Ian Blackford from a position of leadership.”

Mr Grady and the SNP have been approached for comment.