Hundreds of thousands of council workers have begun a two-day strike over pay, marking the beginning of a week of industrial action across the public sector.
The Unison and Unite unions expect around 600,000 workers to join the 48-hour strike in England, Wales and Northern Ireland. The action will hit schools, libraries and refuse collection, close civic offices and sports centres and disrupt other local authority services on Wednesday and Thursday.
Unison members in Scotland will also be balloted on proposals to take similar action north of the border.
Unison general secretary Dave Prentis said: "Striking is never an easy option and not something that we do lightly.
"We urge the employers to sit down with us and discuss a fair and equitable solution."
Prentis also claimed the industrial action would be one of the biggest since the general strike of 1926. Speaking on the BBC Radio 4 Today programme, he said that efficiency savings meant local authorities had up £3bn in unused resources that could be used to fund increased pay awards.
But John Ransford, deputy chief executive of the Local Government Association (LGA), rejected the idea that billions of pounds were lying in bank accounts as "simply not true" and said it would be "crazy" to use any money held in reserve to add to an already "fair" pay offer.
Officials from the Home Office, Identity and Passport Service (IPS) and Driving Standards Agency (DSA), amongst others, also intend to take part in the nationwide industrial action over the next 10 days.
Members of the Public and Commercial Services Union (PCS), also represented in the Valuation Office Agency (VOA), Land Registry and Maritime and Coastguard Agency (MCA), have decided to co-ordinate their action with other public sector unions.
PCS general secretary Mark Serwotka said his members were "standing shoulder to shoulder" with other public sector workers over what he says are below-inflation pay rises.
"Inflation is at an 11-year high, not because of public sector wages, but because of soaring food, fuel and housing costs," Serwotka said.
"Experts agree that public sector workers' pay is not the cause of inflation. This vindictive policy of pay cuts, targets some of the lowest paid who deliver the every day services we take for granted.
"The government needs to think again and wake up to the misery that it is causing. We are meeting ministers to press for a change but we will continue the fight alongside our trade union colleagues if necessary."
Amid fears that UK border security could be jeopardised by the action, a spokesperson for the UK Border Agency said: "The security of UK border controls will be maintained. Contingency staffing plans are in place to ensure the public receive business as usual service."

Dods Parliamentary Communications Ltd