by Steve Schifferes BBC News Online economics reporter

Paul Kenny, one of the leading candidates to replace John Edmonds as boss of the giant trade union the GMB, is a long-time union activist who now heads the London region.

In an interview with BBC News Online, Mr Kenny stressed his working class roots and his desire to fight for justice for low-paid workers as his key qualifications for the post.

It is becoming increasingly difficult to explain to them why New Labour continues to bite the hand that feeds it

Paul Kenny, GMB

And he has made his opposition to Mr Blair's approach to the firefighters' dispute clear.

In a statement, Mr Kenny said that "GMB members are sick and tired of the vilification of trade unionists emanating from Downing Street. It is becoming increasingly difficult to explain to them why New Labour continues to bite the hand that feeds it."

However, Mr Kenny has been a strong supporter of the links between the Labour Party and the trade unions, although he is also critical of their approach to employment rights and pensions.

London roots

Paul Kenny's family, Irish immigrants, moved to West London, in the l940s.

Rival Kevin Curran, head of GMB's Northern region

Read a profile

Mr Kenny started work at 15, first at Fuller's Brewery in Hammersmith and then as an apprentice gas fitter.

It was when he became a park keeper in Hammersmith (employed by the local borough council) that he first became active in his local union.

In December 1979, as many trade unions officials decided to retire after Mrs Thatcher's election victory, he joined the GMB as a full-time official, risking his home as well as his job (he lost his tied cottage and had to apply to the homeless persons' unit of the council).

His says his motivation was a fierce opposition to injustice at work, and belief that he could make a difference - and especially his ability to recruit others to his cause.

Thatcher years

He says that, after 18 very difficult years of Conservative rule, with the union movement "decimated," he looks forward every day to having Labour back in power.

Mr Kenny was an early supporter of Mr Edmonds, who became head of the GMB in 1986 with a mission to modernise the union.

He became head of the GMB's London region, with considerable autonomy, in 1991.

He then fell out with Mr Edmonds, over the issue of Mr Edmonds' treatment of the GMB own staff at headquarters, whom Mr Kenny represented.

He says he was also increasingly disillusioned with the top-down leadership of Mr Edmonds, whom he found out of touch with the day-to-day needs of the membership, and who tried to reorganise the union from the top down.

He now believes that Mr Edmonds' high-profile campaign against the government's plans to privatise the public services may have proved counter-productive, depriving the union movement of some smaller, quiet victories they might have had over issues like the minimum wage.

However, he maintains his own opposition to PFI, and is determined that the government now delivers on its pledge - made at the Labour Party conference - to meet union worries on such issues as the two-tier workforce in privatised schemes.

Membership drive

Mr Kenny has made it his mission to recruit more members to the union.

He says that under his leadership the London region has grown from the seventh to the second largest region (out of 10 in the GMB), with a growth rate of 7.5% per year.

Mr Kenny has introduced a new organising structure, with some officials concentrating on recruiting while others provide services to existing members.

And he has straightened out the region's finances, in contrast to the national GMB, which is still running a substantial deficit.