Miners' leader Dave Hopper in Gala day plea to back Jeremy Corbyn

The general secretary of Durham Miners’ Association said the Islington MP’s election as leader was "probably the most important political event in the labour movement since 1945".

He said the party has doubled in size since he was elected with a landslide victory last September and members should be uniting against the Conservative Party.

More than 100,000 people are expected at the 132nd Durham Miners’ Gala on Saturday, and as usual, it will feature displays of banners from former colliery communities and trade unions, marching brass bands and family activities and attractions in the city centre.

Labour party leader Jeremy Corbyn speaks to crowds at the Durham Miners' Gala last year

It was already expected to be well attended as Mr Corbyn is to address the crowds for the second year running.

But organisers are expecting even more interest, given the highly charged political climate following the country’s decision to leave the European Union in last month’s referendum.

Mr Corbyn has faced a vote of no confidence from his own MPs and widespread resignations from his shadow cabinet.

In the official Gala programme Mr Hopper said: “Jeremy’s election was emphatic endorsement of socialist principles.

“It has transformed a party in decline, wrecked by professional self-serving careerists, into one which could galvanise the country against the imposition of austerity.

“Predictably, the establishment has united in fomenting a tsunami of hatred against Corbyn and (shadow chancellor John) McDonnell. They are derided as being ‘out of touch with the electorate’. If this is so true then why are the rich and privileged so bothered?

“Could it be because they fear that the opposite is true?

“Do they fear that Jeremy’s campaign against an increasingly unequal society is resonating with an electorate that increasingly expresses a widespread hatred of bankers and tax dodgers?”

Last week, Mr Hopper said "traitorous" MPs who refused to back MP Corbyn would be receiving letters rescinding their invitation to share the platform at the popular socialist event on the city racecourse.

He said: “Opposition from the enemies of working people is to be expected.

“What is totally unacceptable if the refusal by some Labour MPs to accept the democratic will of party members.

“Just when the Tories are tearing themselves apart over Europe these dissidents are doing their best to undermine and weaken the leadership.”

Left-wing stalwart Dennis Skinner, known as the Beast of Bolsover, has replaced deputy Labour leader Tom Watson as a Gala day speaker alongside Mr Corbyn, Frances O’Grady, of the TUC, Tim Roache of GMB and Mick Whelan of ASLEF.

In his address, Mr Hopper said: “It is a far cry from the days when Tony Blair refused to attend what the biggest celebration of working class solidarity and community values in Europe.

“However, in hindsight, I think it was a blessing that the now totally discredited warmonger, whose actions destabilised the Middle East and gave rise to the so-called Islamic State, never sullied our platform.

“It would have been an insult to our mining families and our history.”

Mr Hopper also praised the former miner, Bernard Kenny, who was injured when trying to save Yorkshire MP Jo Cox who died after she was shot and stabbed in her constituency a week before the referendum.

He said: “Jo embodied the spirit of the labour and trades union movement; someone who fought for justice for those who had no voice.

“She understood the true value of unity about division and the need for international comradeship.”