Dozens of jobs are set to be lost at Europe's biggest granite quarry in Argyll.

Glensanda Quarry operator Aggregate Industries has tendered out excavation works to contractor Oban Earth Works.

As a result, 25 of the 50 the workers currently employed there are expected to be let go.

The GMB Scotland union has threatened to take legal action over the move.

Union organiser Gary Cook said: "Despite our best efforts Oban Earth Works are not prepared to listen.

"We have been at pains to point out that the employees are protected under the regulations which protect employees' jobs and terms and conditions when a contract is transferred to a new employer.

"They are simply sticking two fingers up at the regulations and the hard working employees formerly of Hargreaves.

"This is a terrible time for GMB Scotland members working at the quarry."

Jon Simarro, director of Oban Earth Works, said he represents a "considerate family business".

"We are highly committed to doing everything we can to reduce these as far as possible and employ as many local people as we can," he said.

"Although details are still being finalised, it looks highly unlikely that there will be any compulsory redundancies at this stage and we are working hard to redeploy any affected employees to vacancies on Glensanda or any other opportunities within Oban or Scotland-wide.

"A full employee consultation process is now underway as supported by a Union representative as requested by GMB members.

"Oban Earth Works appreciates the impact these changes may have on the employees and local community, and commits to supporting every employee throughout the process. W

"We are excited about the five years contract on Glensanda and realise that we can't do that without experienced motivated staff working with us to make this contract a success."