"When the capitalist press attacks a man like Bob Crow it shows you what a good job he's been doing," says Durham Miners Association leader Davey Hopper.

Hopper is as devastated as the rest of Britain's labour movement at the untimely death of the RMT general secretary, but his assessment of Crow owes nothing to diplomacy.

Durham miners showed their constant appreciation of the RMT and its leader while he was alive and fighting because they could rely on their backing.

"He always supported miners' struggles and all workers' struggles. He was the light at the end of the tunnel, a breath of fresh air," says Hopper.

It is a rarely bestowed honour for trade unionists and politicians to be asked to address the annual Durham Miners' Gala, but Crow was invited three times and delighted his huge audience with his hard-hitting and principled speeches.

The prospect of sharing a platform with Crow was too much for Labour leader Ed Miliband three years ago when he turned down his invitation.

Asked by Morning Star parliamentary correspondent Roger Bagley at a subsequent press conference if he had done so out of fear of being pilloried as Red Ed by the Murdoch press, Miliband said the reason he had not attended the gala was quite simple.

"I did not want to speak on a platform with Bob Crow. The reason for that is Bob Crow is not a supporter of the Labour Party and he does not support the kind of trade unionism that I think will take this country forward."

Crow would certainly have agreed with Miliband's charges.

He regarded the Labour Party under Tony Blair as having turned its back on the working class and his idea of trade unionism was that it must encompass class struggle rather than class collaboration.

Militant trade unionism was in his blood. His father George was a docker and member of the Communist Party.

When Bob started work in the permanent way department of London Underground, he was involved very quickly in the National Union of Railwaymen, the forerunner to the RMT.

His duties included maintenance of the rails and clearing trees that encroached on the track, leading him to describe himself as a London Underground lumberjack.

He was sent on several international delegations by the union.

On a trip to the German Democratic Republic, he met a young representative from the train drivers' union Aslef, Mick Rix. They were both from Communist Party families and equally committed to militant trade unionism.

"We were treated very well and were very impressed by the peace movement in the GDR," says Rix.

"We also became firm friends and took part in an international football tournament, reaching the final, but he kicked my foot in one game even though we were on the same side and I ended up in fucking hospital."

Crow, who become the NUR national officer for track workers in 1985, was elected assistant general secretary of the RMT, following the NUR merger with the seafarers' union NUS, in 1991.

He remained a member of the Communist Party, in the same branch as industrial organiser Kevin Halpin, until 1995 when he joined Arthur Scargill's Socialist Labour Party for a few years.

"Bob was consistently militant and on the ball politically. The only difference he had with the Communist Party was over the Labour Party," says Halpin.

Indeed, the RMT leader endorsed Communist Party general secretary Rob Griffiths in the 2005 general election, calling him "a champion of workers' rights."

After Rix was elected Aslef general secretary in 1998, his friend Crow emulated this achievement in 2002 following the tragically early death of Jimmy Knapp.

Both rail union leaders were involved in the Fed Up With Losing group, combining trade unions, the TUC women's network and the Morning Star in posing an effective left trend within the TUC. Union leaders involved were dubbed the "awkward squad."

This posed no difficulty to Crow as a lifelong Millwall FC supporter, identifying with the Lions fans' chant of "No-one likes us, we don't care."

He was particularly pleased with a signed photo sent by former Millwall manager Dennis Wise, captioned "From one striker to another."

Despite the media image of an aggressive and abrasive person, those who knew him best have a different picture.

Former RMT Scottish organiser Phil McGarry, who was prevailed upon by Crow to take up a part-time political liaison officer job on retirement, insists: "Bob is genuinely loved by RMT members."

McGarry remembers meeting him on the NUR executive committee in the mid-to-late 1980s and being impressed by his "honesty, keeping the members in his heart and fighting tirelessly for social justice."

Crow's success as a trade union leader was enhanced by his refusal to restrict himself or his union to simply bread-and-butter issues, as important as these are.

McGarry's "part-time" job entails working with the People's Assembly, the Morning Star Campaign Committee, the Scottish Campaign Against Euro-Federalism, the Venezuela and Cuba solidarity campaigns and engaging with politicians in the Scottish Parliament, setting up an RMT parliamentary group similar to that in Westminster.

Retired RMT ex-president Tony Donaghy remembers him as a "straightforward comrade."

"Bob would support people when they were doing something right, but he would also constructively support them when they were doing wrong in a comradely fashion.

"He would say it's nice to be told what we've done right, but I'd rather be told what we're doing wrong so that we can learn from our mistakes."

Institute of Employment Rights director Carolyn Jones recalls the establishment of the United Campaign for the Repeal of Anti-Trade Union Laws in 1998, chaired by Crow.

"A man with principles like Bob who never wavered in his determination to represent his members knew that the anti-union laws had to go, so he was its natural chairman," she says.

The united campaign was successful in mobilising the labour movement in the struggle for a Trade Union Freedom Bill, which was presented to Parliament at a massive meeting in Westminster, but victory still eludes the movement on this issue.

Bob Crow never made the mistake of wholesale attacks on the media, insisting always on drawing a distinction between the capitalist outlets and the Morning Star.

He successfully urged his union executive to follow the lead of the Fire Brigades Union in taking up a seat on the management committee of the PPPS co-operative society that owns the Morning Star.

Stuart Hyslop, who was the first RMT nominee to sit on the PPPS management committee, recalls: "Whenever I needed guidance, support and advice, Bob was always there. He did so much at every level for the paper. He was a leading voice for change."

That leading voice is now silent, but the principles of trade union solidarity and socialist revolution that drove Crow will inspire new generations of working people.

Bob Crow, who was just 52, is survived by his partner Nicky and four children.