Former Labor deputy premier and treasurer Terry Mackenroth has died less than a fortnight after being diagnosed with a lung tumour.

He was 68.

Mr Mackenroth had been optimistic of surviving the tumour, which was found during treatment for pneumonia at the Mater Hospital, but the Labor stalwart’s health declined quickly.

The diagnosis came 20 years after he overcame lung cancer.

The Mackenroth family released a statement, saying they were “heartbroken” and that Mr Mackenroth died on Monday afternoon.

“Terry was determined to fight the cancer, however the tumour was too aggressive and, following his recent pneumonia, it was a battle he just couldn’t win,” the family statement said.

Mr Mackenroth retired as an MP in 2005 after 28 years in the Queensland Parliament, his career bridging three periods of state politics – from the Labor wilderness years when Joh Bjelke-Petersen and the National Party ruled the roost, through the ALP’s renaissance under Wayne Goss and finally through to the Beattie era.

He was elected in 1977 to the Brisbane seat of Chatsworth and spent 12 years in opposition until Mr Goss led the ALP to power in 1989.

A statement said the Mackenroth family was “heartbroken”. Photo: AAP

Mr Mackenroth became minister for police and emergency services, then took on the portfolios of housing and local government before Labor was briefly sent back into opposition in 1996.

In 1998, Mr Mackenroth returned to the ministry under new premier Peter Beattie, and became deputy premier in 2000 when Jim Elder resigned during the electoral rorts scandal, with Mr Beattie admiringly declaring he needed “a tough son of a bitch” by his side.

Mr Mackenroth was treasurer from 2001 to 2005, earning the accolade “Magnificent Mackenroth” from his leader when he delivered a surplus.

Known as “the Fox” for his political wiles, Mr Mackenroth used his gravelly voice and straightforward approach to contrast with some of the more colourful behaviour and rhetorical flourishes of Mr Beattie.

He prided himself on his gruff demeanour and plain style, avoiding what he felt were unnecessary embellishments and games by other parliamentarians.

Former premier Peter Beattie declared Mr Mackenroth “a tough son of a bitch”. Photo: ABC

After leaving parliament, Mr Mackenroth was caught up in a controversy as a lobbyist and property industry director, when it was alleged that he had inappropriately used his intimate knowledge of the SEQ Regional Plan which he had been instrumental in creating.

He was cleared of all misconduct allegations.

He quit as a lobbyist but remained heavily involved in public life.

In 2006, he was a member of the Cyclone Larry Operation Recovery Taskforce and chairman of the appeal.

A year later, he was appointed to the Local Government Reform Commission.

In 2013, he was chairman of the Queensland Floods Appeal.

He became a trustee of Q Super in 2016 and was active in the administration of rugby league and netball.

Mr Mackenroth is survived by his wife, two daughters and four grandchildren.

-ABC