The time has come to mobilise workers to demand "a trade union freedom deal",
the head of the RMT rail union says.
The conference will hear from Chancellor Gordon Brown
Asking politely for reforms to trade union legislation had got workers "nowhere", Bob Crow told media at the annual TUC conference in Brighton.
A union deal should include the right to take solidarity action, he said.
BBC correspondent Stephen Cape said last month's unofficial strike at BA in sympathy with sacked Gate Gourmet catering staff had revived such calls.
But our correspondent said the government would be likely to resist attempts to go back to what they regard as the industrial relations of the 1970s.
Mr Crow said unions needed to demand "basics like the right to strike and take solidarity action, the right to be accompanied by a trade union rep, the removal of restrictive balloting and industrial action notice."
The T&G union has also called for sympathy strikes to be allowed in certain defined circumstances.
Union delegates are arriving in Brighton for the conference held this week.
The agenda includes a speech by Chancellor Gordon Brown, debates on pensions and dealing with the far right.
The GMB union said the government had to decide to repeal the legislation or outlaw abuses perpetrated by employers.
The TUC's head of equality and employment rights, Sarah Veale, said pensions would also be high on the conference agenda, and that delegates would hear from Work and Pensions Secretary Alan Johnson.
She said although employment rights and pensions are regularly debated at the TUC conference it was not because nothing ever changed.
"I think we are making plenty of progress, but we are always there to try to push things along," she said.
The TUC would also be pressing the government on its election promises to look at state redundancy pay, at backing unions in helping employers improve diversity, and at providing more opportunities for people to get further education while in employment, she added.