LABOUR has been thrown in to pre-election chaos in its Scottish heartlands after being sued by one of its own stalwarts.

The party is already facing its biggest electoral threat in central Scotland for decades, with polls predicting an SNP landslide in core industrial constituencies.

But now it also must defend itself from court claims that it wrongly dismissed a whistle-blowing North Lanarkshire councillor who was investigating a multi-million-pound housing repairs contract.

Tommy Morgan has announced he will petition for a judicial review of North Lanarkshire Council's Labour Group's vote to sack him as the local authority's main internal watchdog.

Mr Morgan, who has represented Airdrie for decades, was ousted from his post as convenor of governance and audit late last year by just 16 votes to 14 as the local party split along factional lines.

His allies say his dismissal came after he questioned plans, since completed, to renegotiate a controversial deal with Mears Scotland, a firm run by Willie Docherty, husband of Labour's Glasgow Lord Provost Sadie Docherty.

His foes, however, link his sacking to bitter row with party colleagues on school closures.

Insiders stress the dispute has re-opened age-old wounds in North Lanarkshire Labour, not least as local MPs, and the councillors who have second jobs as their assistants, watch polls suggesting a near total wipe-out in May's General Election.

Mr Morgan, in a statement breaking his silence on his dispute, said: "The irregular and questionable procedures used to remove me from the convenorship of the Audit and Governance Panel has caused damage to my political and personal reputation.

"My family has been put under severe stress and strain: my family name has been besmirched.

"I fully intend to pursue my case through the proper legal procedures. "As such the matter is now in the hands of my counsel to petition for a judicial review."

North Lanarkshire this year formally allowed Mears to forgo millions of pounds in expected savings on housing repairs, effectively transferring losses on to council tenants.

Leader Jim McCabe has admitted being friends with Mr Docherty of Mears but has insisted his friendship played no part in council decision-making.

The Herald earlier this year revealed that Mr McCabe had met Mr and Mrs Docherty on holiday in Ireland on several occasions and that he regularly socialised with the couple.

Mr McCabe, however, denied Mr Morgan's sacking had anything to do with his investigation in to the Mears contract or his watchdog role.

The council leader previously said: "I'd like to make it abundantly clear that I had absolutely no complaint regarding Tommy Morgan's work, ability or the way he handled his position as chair of audit and governance."

It is not clear when Mr Morgan's case will come to court.

Scottish Labour does not exist as a legal entity and the councillor has been forced to sue the party's London HQ.

It is understood Mr Morgan has already exhausted internal Labour appeals against his dismissal.

A spokeswoman for the SNP condemned Mr Morgan's sacking.

She said: "There is no place for this kind of behaviour in Scottish politics - those who speak out against alleged foul play should not face adverse consequences.

"This will damage Labour's standing in Lanarkshire and Scotland even further as we approach the General Election.

"These serious allegations must be properly investigated by Jim Murphy, rather than being swept under the carpet."

Neither the Scottish Labour nor North Lanarkshire Council had any comment.

The Morgan case, meanwhile, will be heard in North Lanarkshire Council again this week.

Two former SNP councillors, Alan O'Brien and Frances McGlinchey, have lodged a motion calling for the "exceptional" Mr Morgan to be re-instated immediately.