Ed Miliband dismissed accusations he was running an electoral risk by speaking at the Durham Miners' Gala on Saturday, insisting he was proud to "follow in the footsteps" of past Labour greats.
The Labour leader spoke before an estimated 100,000 people at the Gala, becoming the first Labour leader to do so since Neil Kinnock in 1989.
Conservative co-chairman Baroness Warsi had earlier claimed that Miliband's appearance reflected his reliance on "militant, left-wing paymasters". She also accused the opposition leader of "handing his party back to Kinnock".
Addressing the crowd at the old Racecourse, Miliband took aim at bankers, Rupert Murdoch and the “rip-off" of Britain's energy companies.
He went on to list several Labour heroes who had stood in the same spot, including Clement Attlee, Harold Wilson, Barbara Castle and Keir Hardie.
Miliband began the day on the balcony of the County Hotel, watching, as Labour leaders had done for many decades, the 80 or so miners' banners and brass bands that paraded past.
Following his speech, Miliband refuted claims that attending the Gala would damage his party's position in the polls.
Taking aim at Warsi, who had earlier accused "Red Ed” of using the Gala to “cosy up to his militant, left-wing union paymasters,” and of “driving the Labour Party away from the centre ground of British politics," Miliband said: "The stakes are so high in this country.
“If you are someone who is looking for work, whose living standards have been squeezed, or someone worried about the NHS, you're not thinking why's Ed Miliband going to the Durham Miners' Gala, you are thinking what can Ed Miliband do for me".
Miliband added: "When you see people marching past as I did from the balcony of that hotel, a march people have been doing for 140 years, I think that it is not just about politics, it is about the strengths of these communities.
"The idea that the people here are a bunch of militants, as some of my opponents say, is nonsense."
His appearance at the event - billed as the largest remaining working class demonstration in the country - has been welcomed by local trade unionists and party activists.
Dave Hopper, secretary of the Durham Miners' Association said it was only right the Labour leader attended.
“Mr Kinnock was the last to speak at the Durham Miners' Gala in 1989 but "all those jokers before him should have come too," Hopper said.
"In a county that is totally Labour-controlled and where every MP since time immemorial has been Labour, Blair, Brown and Kinnock refused to come. It was an insult to the voters in the county. "We are pleased Ed Miliband will be here, he has broken the trend and long may it continue."
"It was worth waiting 23 years for that type of reaction. I was impressed (with the speech). I was more impressed with the courage he showed in coming."
"He came onto the gala field, into the lion's den if you like."
Hopper also disagreed it was an electoral risk for Miliband to come.
"He is among friends and comrades," he said. "I don't know what the attendance was yet - many, many thousands of people - and I cannot see how that will have done his chances of getting elected any damage whatsoever."
Miliband's 11-minute speech was warmly received by the crowd on the Racecourse - the cricket pitch used by Durham University.
He concluded it by vowing to rebuild Britain, saying: "We understand our task for the future - to rebuild our country... on the values of the people of Britain: responsibility, community, fairness, equality and justice.
"That's our mission, that's our task, that's the battle we can win together."
Miliband was surrounded by well-wishers as he made his way from the stage to the Labour Party tea tent.