Union leaders have threatened to stage a second national strike unless agreement is struck with Government when crunch talks start on Wednesday.

As public servants began to lift pickets across the country, officials revealed they were prepared to consider temporary measures to slash payroll costs without pay cuts.

It is understood proposals being tabled include extending the working day, changing flexi-time arrangements and reducing overtime bills.

Hospitals, schools, social welfare offices and local authorities shut down as workers staged walkouts around the country over plans to slash 1.3 billion euro from the public sector wage bill.

Peter McLoone, Impact general secretary, said intense talks would continue over the weekend in a bid to avert a second strike on Thursday December 3 - just days before the Budget.

"The negotiations we are about to enter into, in our judgment, will be difficult, challenging and complex," he warned.

"I believe it is possible to agree an alternative that will achieve the savings the Government requires in 2010 and beyond while rapidly agreeing and introducing reforms which will protect public services and the incomes of those who deliver them."

Around 250,000 public servants downed tools around the country with pickets mounted at several Government departments, outside the Dail and at prisons and fire stations.

However, flood relief workers and emergency staff in Clare, Galway and Cork were allowed to continue work to deal with the worst flooding in living memory in parts of the west and south.

Union leaders said critical medical services, including intensive, elderly and maternity care as well as cancer services would not be affected.