Workers' rights should be guaranteed before the Government triggers Article 50 to take the UK out of the European Union, according to the TUC.
The union organisation issued a series of tests it said should be applied to make sure workers do not pay the price for Brexit.
Jobs, industries and services at risk from leaving the EU should be protected and EU citizens working in this country must be guaranteed the right to remain, said the TUC.
General secretary Frances O'Grady said: "We hope the TUC will have a central role in the coming years of Brexit negotiations and discussions, so we can protect the interests of working people and their families.
"Working people must not be made to pay the price of the vote to leave the European Union. If we rush headlong into Brexit without a water-tight plan for jobs and industry, the living standards of working people will suffer.
"How we plan for Brexit will affect people's lives for many generations and for many governments to come. If Brexit negotiations serve only narrow or elite interests, it will cause deep national divisions and make Britain's future far less stable and secure.
"There is no existing model for this - we need time for a national conversation to create a new 'British model' for a relationship with the EU and the world that is fair and balanced for everyone across the UK."