Transport and General Workers Union leader Sir Bill Morris has challenged the government to give British workers protection fit for the 21st Century labour market.
Morris: Better rights needed
In a speech to delegates on the first day of the TUC annual congress in Brighton, he said there could be no rest until all workers were granted fundamental rights.
Meanwhile left-winger and RMT boss Bob Crow called for new rights so that unions could carry out secondary strike action, something which was outlawed under the Conservatives.
He cited a dispute where a bus company brought in workers from other companies during a dispute - but unions could not bring in its members at those companies to protest.
"If it is good enough for the bosses to understand what solidarity is then it should be good enough for us to bring in laws that create secondary action that is legitimate as well," he told delegates.
Mr Crow then won loud applause from the conference floor when he said all workers should get the same employment rights from day one of getting their job.
Sir Bill raised the case of 86 workers who were sacked while on strike, who then won their case before a tribunal - but never got their jobs back.
Under the existing so-called eight-week rule employers can dismiss workers after eight weeks of a legal strike.
Sir Bill accused ministers of "sitting on their hands" by not doing anything to help those employees who had not been reinstated despite winning their cases.
TUC general secretary Brendan Barber said the government needed to respond to some of the concerns of its key supporters.
Mr Barber - who is due to deliver his keynote address to congress on Monday - told the BBC: "I think we are going to see a lot of frustration with aspects of government policy advocated very strongly."
Opening the conference TUC president Nigel de Gruchy urged the government to address the difference in pay levels enjoyed by executives and those of workers.
During his speech to congress, he said public sector workers were among the lowest paid in the country and he predicted their conditions would worsen if their jobs are privatised.
Sir Bill has also called on the government to change the insolvency laws to stop businesses using a legal loophole to avoid paying workers compensation.
Under the current law, unscrupulous businessmen can sack their workers, declare their companies bust, buy up the assets and then restart trading without having to pay the sacked workers a penny.
Rebuke for CBI
Sir Bill said: "If that's not the justification needed for fundamental reform then frankly what is?"
In a newspaper article on Monday, the T&G leader criticised business association the CBI for supporting a "backward" employment culture.
At the same time as the unions go on the offensive over rights for workers and public sector reforms, they are also threatening to cripple Labour's finances by blocking a funding deal.
Both the Guardian and Daily Mirror said a five-year deal for £40m in funding, crucial for the campaign for the next general election, had been blocked.
The unions want smaller annual - or even shorter - deals to give them more leverage over Tony Blair.
BBC labour affairs correspondent Stephen Cape told Radio 4's Today programme that the big unions felt they were not getting enough return for their investment in Labour.
"Some of the big unions will say 'we've got to stay inside Labour, we mustn't move away, but we have got to sort out the financing and we've got to separate that from the issues, the policy issues that we're concerned about'."