TRADE Union Congress 2015, set to begin this Sunday, will be the most important such summit for many years.

Britain’s labour movement is readying itself for a fight.

The gung-ho class warriors in Westminster’s true-blue government do not intend to play by the usual rules of the parliamentary game. That’s been clear ever since David Cameron scraped a slither of a majority with 24 per cent of the electorate’s vote in May.

There was no sitting back, taking stock, reflecting on what the long-term consequences of the increasingly polarised and fragmented political scene in Britain might be.

It was only a matter of hours before the Tories cut access-to-work funding for deaf and blind people and only a matter of days before Business Secretary Sajid Javid was unveiling the contemptible assault on working people’s rights that is the Trade Union Bill.

The Bill is an extremist, authoritarian assault on the largest democratic organisations in the country, our trade unions, which together form a movement many millions strong — dwarfing the size of any political party.

The arrogance of the Tories leaps out from every line. It’s one rule for the rich, another for the rest of us.

Workers already have to leap through a succession of flaming hoops just to withdraw their labour in a strike.

Further restrictions planned — imposing a minimum turnout of 50 per cent in strike ballots and insisting in “essential industries” that at least 40 per cent of the eligible electorate vote in favour of action.

This means counting every abstention, lost or spoilt ballot or failure to take part as a No vote. No election conducted under such rules would have returned Cameron to Downing Street — the stay-at-homes outnumbered the Tory voters by more than four million.

And that’s not all they want to do. Ongoing “consultations” are looking at how to force unions to tell their employers, the police and other bodies what their members plan to say on Facebook and Twitter during disputes — with the possibility of massive fines for “unauthorised” comments — and appoint picket supervisors with special armbands who must hand over all their personal details to the police.

Yesterday’s stark warning from Liberty, Amnesty International and the British Institute of Human Rights that all this constitutes “a major attack on civil liberties” which “hamper[s] people’s basic right to protest and shift[s] even more power from the employee to the employer” is spot-on.

Those critics of the Bill who accuse the Tories of seeking to cripple the unions out of spite and vengeance are of course right, but they’re not seeing the full picture.

Consider the clause seeking to hack away at trade union funding for Labour, thus hobbling the finances of the opposition while leaving the hedge-fund managers and City gamblers free to pour their ill-gotten gains into Conservative coffers.

There is method to this madness. The Conservatives are conducting class war, pure and simple.

They are seeking to rewrite the rules so ordinary workers can never win. And they’re targeting trade unions because they know these are still the most powerful weapon working people have.

In Brighton from this Sunday we will hear, loud and clear, our movement’s response.

And Congress will open the day after we discover who the leader of the Labour Party will be, after a remarkable summer which has seen hundreds of thousands flock to sign up.

This newspaper has made no secret of its preference. But even if Jeremy Corbyn does not win, we must have a real opposition that ensures the Labour Party stands alongside the trade unions as a force to be reckoned with — a millions-strong labour movement, daring to struggle, daring to win.