The SNP has moved quickly to capitalise on Labour being sued by own of its own stalwarts in its central belt heartlands.

Nationalists will Thursday formally demand a statement on the sacking of veteran Labour councillor Tommy Morgan as North Lanarkshire Council's internal watchdog.

Mr Morgan has announced that he is seeking a judicial review of his dismissal as convener of audit and governance in the local authority.

The stalwart was ousted before Christmas in a knife-edge vote which split North Lanarkshire's ruling Labour Group.

Mr Morgan's supporters say he was dumped because he was investigating controversial moves to renegotiate a deal between the council and Mears Scotland, a firm run by a friend of Labour's North Lanarkshire leader, Jim McCabe.

Mr McCabe's colleagues deny this, saying the sacking came after Mr Morgan used aggressive industrial language in an internal row over schools closures.

The opposition SNP - which has had its own splits in the council over recent years - was quick to capitalise on the legal action.

Its group leader, David Stocks, said: "The press reports that Mr Morgan had written to the council chief executive querying the £30 million a year Mears contract, which has been re-negotiated to the detriment of the Council and where the Council Leader is close to senior officials at Mears.

"This affair stinks. It is time for Labour to tell the public and other councillors what is going on. After all, we are dealing with a key financial watchdog committee."

The SNP has long lobbied for Mr Morgan's former post to be held by one of its own councillors, rather than a Labour one. The party says such watchdogs are opposition in all but three of Scotland's 32 councils.

Richard Lyle, the SNP MSP for Central Scotland and a Mr Stock's predecessor, called on Labour's Scottish leader, Jim Murphy, to look at Mr Morgan's case.

He 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."

Two former SNP councillors - now independents - will call for Mr Morgan's re-instatement on Thursday, when North Lanarkshire holds a full council meeting. Labour - as is customary from bodies being sued - made no comment.