Workers for Aker Solutions at a North Sea platform have started an unofficial strike over working conditions.

A statement from workers say that they downed tools at 7am on Saturday on the Mariner platform.

They planned a four hour stoppage in work to highlight poor working conditions, management and claims of blacklisting former workers.

A statement from J Furie, spokesman for the workers on Mariner, said: "Today brings a day of unofficial actions against working conditions on the Mariner hook up."

A worker added: "We are protesting against poor working conditions, poor management, possible blacklisting and having an offer of a bonus removed.

"This action will escalate if we are continued to be treated this way."

A statement from Aker Solutions said: "Aker Solutions has been made aware that some workers based at the Mariner field have chosen not to work today.

"The company has received no official notification of this activity and is looking into this matter."