Teachers, care workers, fire fighters and civil servants are among those taking part in industrial action.
Earlier this week, Unite national officer Fiona Farmer told HR magazine Unite’s members felt they had “no option” but to strike after years of pay restraint.
Public sector salaries were frozen in 2010 and a 1% pay rise cap has been in place since 2012.
According to research released yesterday by the TUC, since this Government took office a combination of pay freezes and below inflation wage increases have left public sector workers an average of £2,245 worse off in real terms.
TUC general secretary Frances O’Grady, who is joining picket lines today, said the strikes show public sector workers think “enough is enough” and that “ordinary workers” are being "locked out of the recovery".
“Year after year pay has failed to keep up with the cost of living,” she added. “Nearly half a million local government workers earn less than the living wage. But even as the economy starts to grow, ministers have told them that the pay cap will last until at least 2018.”
Prime minister David Cameron has promised to tighten strike ballot laws as part of next year’s Conservative general election manifesto.
He told MPs: “I don’t think these strikes are right… the time has come for looking at setting thresholds in strike ballots. It is time to legislate and it will be in the Conservative manifesto.”
Conservative proposals revealed earlier this week include withdrawing legal protection for striking workers unless unions can prove that half or more of their members had voted for the strike, and preventing unions from taking action on mandates that are more than two years old.