Patients may face disruption later this month after a major public sector union served notice of industrial action on the HSE.

A Fórsa spokesperson said formal notice has been issued to health employers of a work-to-rule to start on Wednesday September 30 in a dispute over public sector pay.

It is the first notice of industrial action to be served in the dispute that involves 19 unions with public sector members. Their leaders found there was no basis for talks on a new public service pay agreement after the last one expired at the end of June.

Fórsa represents staff including clerical, administrative, health and social care professionals and some management grades in the health sector.

The work-to-rule includes a number of actions including a refusal to work overtime or outside agreed contracted hours.

The Fórsa spokesperson said it comes in advance of nationwide industrial action. He said the union expects employers in other sectors will be notified of further industrial action in the coming weeks.

Fórsa’s health and welfare division represents 32,000 members across the public health service.

Notice was served on the HSE, Tusla and ‘section 38’ organisations, which receive state funding.

The union spokesperson said notice was served of a range of “initial targeted actions”.

They including working strictly to contract, role and grade, and include refusing duties assigned to another grade, refusing overtime and work outside agreed contracted hours.

The action also includes a refusal to cooperate with proposals to extend working patterns across a seven-day roster.

Fórsa members will also withdraw cooperation from HSE and Tusla restructuring and implementation processes.

They are set to refuse to cover duties attached to vacant or unfilled posts, complete national financial, data and performance reports, or engage with external private management consultants.

The union noted that the industrial relations act requires one week’s notice of industrial action.

However, the spokesperson said it is observing an established convention in health services by serving three weeks’ notice.

He said the additional notice period reflects the essential nature of health services and allows employers to make contingency arrangements.

Fórsa represents members across health, local government, the civil service, education and state agencies.

Over 62,000 Fórsa members voted for industrial action last month.

A total of 96.6pc voted in favour of industrial action, up to and including strikes.

Fórsa head of health and welfare, Ashley Connolly, said the ballot result represents a decisive mandate from its members and reflects growing frustration at the absence of a credible public service pay offer following the expiry of the previous agreement.

“Our members provide vital public services every day,” she said.

“Serving notice today marks the beginning of a planned and proportionate escalation by public service workers who have made clear that the Government’s current position on pay is not sustainable.”

Fórsa national secretary Ryan McKinney said members voted overwhelmingly to act because Government failed to engage seriously on a pay offer that addresses the pressures faced by workers.

Expenditure minister Jack Chambers yesterday said it would be “deeply unfair” to the public if there is significant disruption due to industrial action over public servants’ pay.

He rejected claims that their earnings have lagged behind the cost of living.