But Lewis Ritchie has confirmed he will still represent his Leith ward as an independent.
Cllr’s Ritchie’s decision means the SNP will no longer hold the highest number of seats in the council, instead tying with the Tories.
His decision to leave the SNP was criticised last night by his former party colleagues.
A spokesman for the SNP group on City of Edinburgh Council said: “Councillor Ritchie resigned from the party because there were a number of complaints regarding his behaviour. He should consider whether he is fit to represent his constituents as an independent councillor.”
The move takes the SNP down to 18 councillors – level with the number of Conservative representatives.
In a Facebook update posted yesterday, Cllr Ritchie said: “I have the honour of representing Leith Walk as an independent councillor.
“As an independent, my ward and the people I’m proud to represent will always be my number one priority.”
He is the only independent on the city council.
The councillor has also updated his Twitter handle and biography to reflect his departure from the SNP and change to independent status.
Cllr Ritchie was suspended from the SNP following a complaint over an alleged physical incident at the party’s conference last year.
The councillor is accused of hitting another delegate during an alleged fracas in a taxi at the SNP’s annual party conference in Glasgow in October.
The SNP’s internal disciplinary committee confirmed that it had been considering a complaint and Cllr Ritchie had been suspended pending a hearing.
Regardless of the outcome of the hearing, Cllr Ritchie was still entitled to remain a councillor, even if he is no longer a member of the SNP.
The Evening News revealed in November that Cllr Ritchie – who was nominated for a top political award just weeks later – had stepped aside from his roles as planning convenor and Leith Walk ward councillor at the City of Edinburgh Council due to “health reasons”, after telling SNP group party leader Adam McVey that he had taken on too much and found it was having a detrimental effect on his wellbeing.
He had been due to return to work on January 7, but it is understood his leave of absence was extended.
Cllr Ritchie was shortlisted – alongside Aberdeen City Council leader Jenny Laing and Susan Aitken, the first SNP leader of Glasgow City Council – for the Local Politician of the Year category at the prestigious Politician of the Year awards held at Edinburgh’s Prestonfield hotel.
A keen boxer and runner, Cllr Ritchie was last year named chairman of the Royal Air Forces Association for Edinburgh, Lothian and Borders and is an army reservist.