More than a million public sector workers are set to take strike action in the autumn unless the Government pulls back from its controversial pension changes, a union leader warned today.
Dave Prentis, general secretary of Unison, said huge numbers of local government workers and NHS staff were "on the road" to industrial action.
Balloting of around 1.2 million workers will start soon unless a crunch meeting with the Government on June 28 leads to a deal.
Mr Prentis said there was a "perfect storm" of pension increases and pay freezes which could lead to public sector workers having their earnings cut by 10%.
Mr Prentis said the Government was now on a "collision course" with public sector unions over pensions as well as cuts to jobs, pay and services.
He accused the Government of preventing proper negotiations over changes to pensions.
He told a press conference: "If we are prevented from reaching agreement we will move to a ballot in the summer or early autumn.
"It will not be one day of action - it will be long term industrial action throughout all our public services to prevent destruction of our pension schemes.
Mr Prentis said planned changes to pensions would lead to public sector workers paying-in more, receiving less in retirement and working longer.
He warned of "massive industrial unrest" later in the year, adding; "It is very clear we are on a collision course unless the Government changes its policies."
Up to 750,000 teachers and civil servants are set to strike on June 30 and Unison is already balloting 30,000 workers for strikes in protest at spending cuts.