Hundreds of health workers in Northern Ireland have voted to strike in a dispute over pay and staffing levels.

GMB members – including nurses, ambulance workers, hospital porters, cleaners and caterers, clerical staff, technicians, care workers, social workers and transport workers – voted for industrial action, with 86% backing the move in a ballot.

The union said it would meet with members to discuss next steps, with strike action possible before Christmas.

The development comes in a week when the Royal College of Nursing will announce whether its members have voted in favour of the first UK-wide strike by nurses.

Also on Tuesday, the union Unison wrote to Northern Ireland Secretary Chris Heaton-Harris to demand an inflation-busting pay increase for healthcare workers.

Announcing the GMB ballot result, union organiser Jim Donley said: “This vote for strike action shows the NHS workforce across Northern Ireland are desperate.

“They’ve faced years of real terms pay cuts, a deadly pandemic and now a crushing cost-of-living crisis. They’re being pushed to the limit.

“But more than pay – this is as much about patient safety. A third of GMB ambulance workers think delays they’ve been involved with have led to the death of a patient.

“The NHS in Northern Ireland is on life support – the Westminster Government needs to provide urgent extra funding or the service as we know it will cease to exist.”

On Tuesday, Unison head of bargaining Anne Speed wrote to Mr Heaton-Harris calling for action on pay in the ongoing absence of a devolved administration at Stormont.

“The absence of a mechanism to uplift pay to health workers in Northern Ireland is a matter of serious concern for the thousands of staff we represent in Northern Ireland,” she wrote.

“Together with all health unions in Northern Ireland, as the lead trade union we have been attempting to find a way forward.

“At this very moment more than 35,000 workers are being balloted on industrial action. One union has already declared a vote for strike.

“This scenario has unfolded as our unions across the UK are also balloting. They are doing so to secure additionality to the imposition of the Pay Review Body (PRB) recommendation.

“All health trade unions within the UK believe an inflation-busting pay rise is necessary to protect struggling working families against the cost-of-living crisis.

“Health workers in Northern Ireland are now voting without having received this minimum payment.

“Pay parity with NHS England restored after a Northern Ireland -wide strike in 2019/2020 and endorsed by the NI Executive has once again been ended.

“Our health workers are angry and feel disenfranchised and this will no doubt be reflected in their response in the ballots under way.

“Given your intention to set a course over the coming weeks we ask you to bring your influence to bear on the Prime Minister to allow scope for and fund further UK-wide uplifts in 2022 to deliver protection against inflation.

“This would also provide scope for you to address the consequent omission of the PRB recommendation here in Northern Ireland, and ensure that a returned devolved Northern Ireland Executive has discretion to additionally resource pay improvement for 2022.”