LABOUR councillors have been threatened with suspension if supporting moves to oust the leader of Glasgow City Council before he quits next year.

The party's Scottish general secretary has also warned members of the city's administration they will also face sanctions if found to be speaking publicly against Gordon Matheson, currently bidding to become Scottish Labour's deputy leader.

In a letter issued by the city council's group whip on the instructions of Brian Roy, the 45 Labour members have also been told that they are suspected of being behind unattributable quotes in the media they will face disciplinary action.

The warning comes as leader of the country's largest council faces unprecedented pressure to bring forward his exit,

with around 20 councillors, just under half of Mr Matheson's group, signing calling for an EGM to discuss his departure.

Several of the instigators of the campaign to accelerate the installation of a new leader continue to seek a showdown with Mr Matheson over his intentions.

Sources close to Mr Matheson have said they believe the number to be "no more than 17" and have cast doubt on the identities of some of those said to be supporting regime change.

Confirming that several around the leader have also been contacting group members to persuade them not to sign, they have also accused signatories to the motion of having no unifying politics and fuelling disquiet amongst ordinary members.

But the intervention by Brian Roy to instruct party whips to issue a warning has upped the ante amid the most significant Labour disquiet on the council for several years.

The note, from Cllr James Adams, states: "The general secretary has explicitly asked me to communicate to the group that this (calling for the EGM) is not the way we in the Labour Party should conduct our business.

"It was made clear to me that that if any evidence is uncovered of any member of the group engaging with this letter from this point forward could face disciplinary action and ultimately suspension if possible."

But one source said: "The concerns seems to be about the impact on the party leadership contest not the Labour group's future.

"This is an command from the people behind Labour's catastrophic loss in the General Election telling us how best to prepare for our own election in 2017."

If he becomes deputy, Mr Matheson secures an automatic right to the top spot on Labour's Glasgow list for Holyrood next year, all but guaranteeing he would become an MSP.

But it has angered many Labour councillors, MSPS and 2016 Holyrood candidates, who accuse Mr Matheson of hoping to catch a "lifeboat" to Holyrood.

He has since agreed to stand down in February, regardless of whether he became deputy or not.

The motion signed by the 20 or so councillors states: "We, the undersigned, hereby request that an extraordinary general meeting of the Glasgow City Council Labour Group is called on 10th August 2015 in order to discuss, agree and stabilise the leadership of the group well in advance of the upcoming elections to the Scottish Parliament in 2016 and to Glasgow City Council in 2017."

But one source close to Mr Matheson said: "Gordon has a very good chance of becoming deputy leader of the party in Scotland.

"How bad does it look if we throw him out before the result is even announced. He has said he will bring forward the annual general meeting by as much as he can and would go early in the New Year, allowing for a stable handover and giving enough time for two clear candidates to emerge."

Amongst those tipped to succeed Mr Matheson are former leader and Scottish minister Frank McAveety and rookie councillor and head of Fair Trade Scotland Martin Rhodes.

A Labour spokesman said the party did not comment on internal party or group matters.