Oil and gas workers at a plant in Aberdeenshire will be balloted over strike action, Unite has announced.

Employees at the Wood Group's St Fergus gas plant will vote on whether to take industrial action over "safety concerns and attacks on terms and conditions", union representatives have said.

According to Unite the union, the dispute arises from the scrapping of daily payments for those who undertake "integral" safety responsibilities.

It is claimed some workers on the Shell-owned site could have wages slashed by up to £103 a week because of changes to payments for those who carry out safety duties and the ability for staff to volunteer to do the role.

Workers at the plant, which processes oil and gas from offshore installations in the North Sea, voted 98% in favour of balloting for industrial action in a consultation, and Unite has now confirmed it will go ahead with the ballot.

Vic Fraser, Unite regional industrial officer, said: "Wood Group has informed us that they intend to unilaterally change contracts to ensure everyone in the workforce may be required to be a permit holder and are obliged to have it without any additional payment.

"Unite will not stand by as individuals who do not want to perform this safety critical role and those individuals who are not even capable to carry out the added responsibilities being forced to do so.

"The permit system is an integral part of the safety system at the gas plant."

He added: "Both Wood Group and the site operator Shell have been made aware of the reduced plant efficiency and the concerns over safety through stopping the original practice of permit holders coming in half an hour before the rest of the workforce.

"But, neither company appears to be interested in what the workforce has to say.

"As such, Unite members will be moving forward with an industrial action ballot to protect our members' terms and conditions, and the safety of the plant and the nearby community."

A Wood Group spokeswoman said: "In line with site activity, we no longer require 36 employees to undertake 30 minutes of overtime to take out permits.

"We are modifying employee terms and conditions to reflect this change, which aligns with other Wood sites.

"Safety remains our highest priority and is not impacted by these changes.

"All employees working in a permit-controlled environment receive relevant training as part of their roles."