NSW murderer jailed for at least 30 years

A Sydney murderer who stabbed a colleague so deeply it severed his spinal cord has been jailed for at least 30 years.

Gordon Reginald Cramp, 38, was last October found guilty of murdering Lance Hargreaves, 62.

His body was discovered lying in a pool of blood at a waste management plant at St Marys, in Sydney's west, in the early hours of February 21, 2013.

Cramp was sentenced to a maximum of 40 years' jail with a 30-year non-parole period in the NSW Supreme Court on Thursday.

It was backdated to begin on March 2, 2013, meaning the earliest he can be released is on March 1, 2043.

During his trial, it emerged that Cramp was sacked in November 2012 for failing to arrive at work, but returned to the plant the night before he murdered Mr Hargreaves.

Mr Hargreaves told a co-worker he couldn't understand Cramp because "he was raving on about something" and kept saying "you owe me big time".

The crown argued Cramp had taken ice and cut a CCTV cable at the site before committing the murder.

This was not this first time Cramp had been sentenced over a stabbing attack.

In 2003, he was sentenced to five years and seven months' jail for stabbing another man in the back near his spine - causing severe lung, throat and torso injuries.

He will now spend at least another 28 years behind bars.