Unions have moved closer to an autumn of strikes as the Government was warned it faces a huge campaign of civil disobedience over spending cuts and "attacks" on workers' rights.
Millions of public sector workers could be taking industrial action in protest at planned changes to their pensions, possibly on November 29, when the Government announces its autumn financial statement.
An announcement could made within days of widespread ballots for action, heralding the biggest outbreak of industrial unrest for decades.
Plans to co-ordinate industrial action will be discussed at the TUC on Wednesday, but sources said a large number of unions were now moving towards balloting for strikes.
At the conference on Monday, delegates agreed to consider a legal challenge against the coalition, alleging breaches of international labour law, and to campaign against "anti-union" legislation.
Officials lined up to attack the Government over its spending cuts and moves to strengthen laws against strikes and other forms of union action.
Paul Kenny, leader of the GMB union, said that if the Government brings in more laws, it would be in response to strikes against public sector pensions, which he warned looked set to be joined by millions of workers.
He said: "Bad laws have to be broken. Civil disobedience in protest at erosion of civil liberties and freedoms have a place in our history. Millions of people inside and outside of trade unions can and will fight. If going to prison is the price to pay for standing up to bad laws, then so be it.
"We will give politicians the biggest campaign of civil disobedience their tiny minds have ever seen."
Len McCluskey, general secretary of Unite, said unions should not "meekly accept" anti-union laws, adding: "If tax avoidance is lawful and unpunished, let's plan for anti-union law avoidance in the same spirit."