A LEADING Labour Party office bearer has quit her post amid post-referendum fallout, citing disillusion with the party nationally.

Aileen Colleran, chairwoman of Glasgow City Council's Labour administration, has stepped down, claiming the party cannot "pretend it's business as usual" and will leave frontline politics at the next local elections.

She announced to colleagues via email at a post-mortem of Glasgow Labour's poor referendum campaign she would be stepping down, a clear blow to the administration and council leader Gordon Matheson.

Ms Colleran, who represents the Partick ward, is also gearing up to stand down in 2017, after 18 years as one of Labour's most prominent Glasgow councillors.

Her discomfort with Labour has been increasingly public lately, sending a message on Twitter in the immediate aftermath of the referendum No vote: "How the Labour Party reacts to results in next few hours + days will decide our future. Gloating/triumphalism = Pyrrhic victory."

Another said: "Scenes of ­celebrating with Tories aren't going to go down well with the folks who voted Yes in my ward. Stand by for the backlash."

A source close to Mr Matheson said: "Aileen's disillusionment with Labour nationally has been shining through of late."

However, Ms Colleran played down speculation among some Labour colleagues she is on the cusp of defecting to the SNP.

She is married to former SNP Westminster candidate and election organiser Chris Stephens.

Ms Colleran said: "My reasons for standing down as group chairwoman are to spend the remainder of my final council term focusing on my ward, one of the largest in population in Scotland. Labour has a challenge to meet locally and nationally and we can't shy away from that and pretend it is business as usual."

SNP group leader Susan Aitken said: "I don't think Labour is a happy place nationally but especially in Glasgow. This is a very visible sign of that."

James Adams, Labour group business manager, said: "Bailie Aileen Colleran has made a significant contribution to the Labour Group in recent years. We fully understand and respect her decision to stand down as chairwoman to focus on serving her constituents between now and 2017."