Dave Prentis, general secretary of Unison, predicted a pay revolt by the end of 2014.
He also raised the spectre of it not happening until 2015 in the first few months of a Labour government.
He said, “We will be working with other unions for an end to this pay cycle.
“There will be major action around pay and it will be coordinated.”
Delegates passed an emergency motion calling for a full inquiry into the Shetland Super Puma helicopter disaster.
Four people died when it crashed last month.
The motion supported workers who refuse to travel on this type of helicopter unless their safety concerns have been addressed.
The TUC passed a motion reaffirming its opposition to Trident.
It also issued a statement opposing military intervention in Syria.
Delegates slammed new plans to make workers with household savings of £3,000 pay the full cost of going to an employment tribunal.
From next month they will have to pay the maximum £1,200 fee even if they are in a low-paid job or on means-tested benefits.
Strikes at 68 universities
Agency workers would be paid more
A racist Tory bill
Many people are already missing bill payments