Construction and engineering workers at Interserve were turned away from a Glasgow recycling plant yesterday after the contractor was axed from its work on the site.

Workers found themselves locked out of the Glasgow Recycling and Renewable Energy Centre (GRRC) at Polmadie when they turned up for their shifts around 6.30am yesterday.

The move came a few weeks after Interserve was given notice that its contract had been terminated by site managers Viridor.

Interserve said it would try to offer redeployment where possible but admitted that “some of the 150 roles are at risk”.

Viridor said it terminated its contract with Interserve, which has been working on the plant since 2013, as a “last resort” due to technical problems and delays.

It has emerged Interserve’s contract ended at midnight on December 7 but some staff appeared not to have been informed and turned up for work as normal yesterday.

An Interserve spokesman said: “Last month we were served notice of termination on the Glasgow Recycling and Renewable Energy project, which came into effect today.

“As a result, we will no longer be working on the project, meaning some 150 roles are at risk. We will, where possible, look to redeploy affected employees in other parts of the business.”

Viridor has now taken on some of the staff, who will continue to work at Polmadie.

A spokesman for Viridor added: “Viridor has terminated its contract with Interserve as a last resort, in the best interests of the project.

“We are moving quickly to ensure continuity of delivery and are working hard to retain the majority of the existing supply chain.”

The Unite union has threatened to take legal action, claiming staff were paid off with just a week’s notice.

And the GMB union has said it will lodge a collective appeal and grievance on behalf of its members. It has called for Viridor to transfer the workers to the new sub-contractor.

GMB Scotland senior organiser Tony Dowling, whose trade union represents some of the staff involved, said: “This ranks among the most callous treatment of workers I’ve came across in years.

“Our members have been kept totally in the dark while relations between Interserve and Viridor were collapsing. Our members have family commitments and mortgages to take care of and they’ve arrived for work only to be locked out of the site and then served with the sack by their employer just two weeks before Christmas.

“The behaviour of Interserve is beneath contempt, but Viridor should do the right thing and ensure that the workers affected are transferred to whoever the new contractor of choice will be for the completion of the Polmadie site.

“In the meantime, we will enact the available appeals processes on behalf of our members to protect their interests as best we can.”

Unite Scottish secretary Pat Rafferty said: “Viridor is getting paid out of public money. It is their inaction that has put our members in this situation. That is completely unacceptable.

“As far as we’re concerned, our members are protected by Tupe regulations. Any employer trying to breach our members’ rights will leave themselves open to possible legal action.

“We urge Viridor to urgently act to sort this situation out and we are calling on Glasgow City Council to help.”

He added: “We are consulting with our lawyers and will do everything in our power to ensure that our members on this publicly-funded project are treated with dignity and respect - and that their legal rights are respected.

“We won’t accept our members being left with this uncertainty - especially at this time of year.”

The £154 million development at Polmadie is one of a number of contracts in Interserve’s exited energy from waste (EfW) business.

The firm revealed in May that it would have to take a £70 million hit on the delayed contract after further deterioration in the project “significantly adversely impacted” its expectations for the UK construction division as a whole.

The issues related to the design, procurement and installation of the gasification plant, together with continuing challenges with the supply chain that will result in further cost overruns and delays.

The project was then months behind schedule and was also subject to strike action the previous month.

Waste gasification specialist Energos, which was involved in an ongoing contract to deliver the Glasgow centre, fell into administration in July.

Interserve then announced it would quit the EfW sector after problem contracts in the sector forced it into a £34m half-year loss.