Len McCluskey, the leader of Britain’s largest union, Unite put the government on notice that it would defy the trade union bill “using any means necessary to defend the democratic rights and freedoms of all trade unionists and the working people of our nation.”

The warning came as Unite called upon the government to end its systematic efforts to paint trade unions and their members as the `enemy within’, driven by a prejudice so intense that the government is willing to jeopardise the basic freedoms of all in the UK.

Len McCluskey said: “This is a movement that has from its inception delivered for each generation continued improvements to the working lives of millions of people.  It has secured our nation’s wealth and fought for the social and political progress that has made this county a place of fairness, equality and social justice.

“But instead of recognising our role this Prime Minister seeks to paint the millions of trade unionists and their families at `the enemy within’, with a Tory party drunk on class prejudice intent on destroying this movement as a force in British life.

“They seek to reduce trade unions to no more than employment advice agencies, while turning our members – who dare to act – into criminals.

“There is though, an emerging broad and united democratic campaign against this legislation is greater than ever before – because it doesn’t just attack trade unions.

“It threatens freedom of speech. It menaces freedom of association. It insults the values which all British people cherish.”

Len McCluskey called for the government to abandon the conflict it is pursuing with the unions and instead work with the movement to modernise voting arrangements:

“Instead of quibbling over percentages, let’s use the language of democracy and modernisation and implement secure workplace balloting. End this archaic reliance on postal ballots, and turnout will never be a problem again.”

The general secretary raised again the issue of when a law is so unjust, can it always be obeyed:

As we celebrate 100 years of women suffragettes fighting for votes, thank goodness that they did not see the law as sacrosanct.

“And had this conference been meeting in the 1960s in the southern states of America, would we have asked our black delegates to sit at the back of the hall – like Rosa Parks – or would we have defied the law?

“Our history, and that of the world, is littered with brave men and women who have defied bad laws and who fought and yes died to give us our heritage.

“And if that history tells us anything, its that when one section of society is segregated, asked to identity itself with labels and armbands and submit to a state-sponsored blacklist, the civil liberties of all of us are put at risk.”