Lawyers are launching legal action on behalf of unpaid former workers at a firm caught up in a row over stockpiling clinical waste.

Hundreds of workers were laid off after Healthcare Environmental Services (HES) ceased trading in December.

Thompsons solicitors said they are launching employment tribunal proceedings on behalf of more than 180 former staff, some of whom say they are owed up to five months' pay.

MSPs were told in January of a backlog of between 250 and 300 tonnes of clinical waste and 10 tonnes of anatomical waste at Scottish HES sites in Dundee and Shotts.

HES has previously denied claims human body parts were among waste stockpiled at its sites but Environment Agency reports said the company stored remains of NHS patients in unrefrigerated units for more than six months.

Thompsons partner David Martyn, who is in charge of the legal action, said: "The former employees of HES were dismissed without notice in December last year. They have now waited three months for their former employer to do the right thing and pay them the wages, notice pay and holiday pay they are owed.

"Some employees are owed up to five months' pay and have had to resort to food banks to support their families. The time has now come for us to begin formal legal proceedings to force the company to pay the money the workers are due."

HES became embroiled in a clinical waste stockpiling controversy with the NHS in 2017, during which it denied claims human body parts were among items caught up in a backlog at its sites.

On Thursday afternoon around 20 workers staged a protest outside the premises in Shotts calling for their wages to be paid.

Greig Drysdale, who worked for HES for six months, said many of his former colleagues are owed thousands of pounds.

He said: "People are annoyed because that's three months without getting a wage. There are quite a few still not working although the majority have got jobs.

"I was only there for six months but I'm entitled to my wages, whether it's six months or six years."

Elizabeth Mellon, who worked at HES for 11 months, said she is owed around £3100.

She said: "I hope HES will see that we're still angry and upset.

"I started working again about five weeks ago and got paid but the wage just went to pay everyone back who had lent me money."

Scottish Labour leader Richard Leonard also attended the protest.

He said: "It's a question of a fair day's pay for a fair day's work but it's also a question of justice. The people that worked here who built this company up have been left abandoned with money owed to them and with lots of questions still unanswered."

HES have been asked for a comment.

The UK Government Insolvency Service said workers who have had a contract for more than two years are entitled to redundancy pay.

It said it has received 158 claims for redundancy and has paid out £464,000 to claimants, with only one claim outstanding.

A spokesman said: "Healthcare Environmental Services has not put itself into insolvency so under law the workers cannot claim for wages owed, notice pay or holiday pay at this time.

"If the company puts itself into an insolvency procedure then these payments could be made."

Sepa said it is carrying out regular inspections of the sites.

A statement posted on the HES website in January said "the directors and senior managers of HES have fought daily for the survival of the business", while owner Garry Pettigrew said he was still fighting for workers.

A Scottish Government spokesman said: "We have supported affected employees through our Pace initiative and will continue to monitor the situation and provide further support as required.

"The company has claimed that their bank refused to release funds to pay salaries.

Minister for business, fair work and skills Jamie Hepburn attempted to intervene in this situation and contacted Mr Pettigrew to seek his permission for the minister to contact the company's bank HSBC. Mr Pettigrew refused permission.

"In response to a request from HES former employees, the minister then contacted HSBC directly, who advised they would require Mr Pettigrew's permission to discuss any issues with the minister.

Mr Pettigrew once again refused this permission.