It was the opinion of Richard Crossman that for all the charisma of Aneurin Bevan himself, for all the organising skill of Ian Mikardo and for all the intellect of the members, the Keep Left and Bevanite groups would never have been the force they were but for the workhorse energies of that "ever-persistent and beautiful girl with the flaming red hair". Jo Richardson in her heyday, and her heyday lasted from 1945 until 1990, was one of the dynamos of the Left in Britain. She was a "cause and issue" politician - against German rearmament, an Aldermaston marcher and organiser of many demonstrations against nuclear weapons, champion of nationalised industries and above all of women's causes.

If women's causes now receive such dramatic prominence in the affairs of the Labour Party their advance is due in no small measure to the day-in-day-out campaigning of Jo Richardson. No group was too insignificant, no organisation too obscure to merit a visit. I suspect that no politician of the modern era has done more meetings per year for her party and the causes that she believed in. My first memory of Richardson is of her storming to the Conference platform at Scarborough in 1958 to deliver a passionate invective backing Archbishop Makarios's proposals for Cyprus and denouncing the British government for being anti-Greek Cypriot.

Jo Richardson was born a Geordie. Her father was a commercial traveller who stood as a Liberal in the Darlington constituency in the 1930s and her mother an ardent Congregationalist. Much of her career derived from experiencing the difficulties her mother faced after her father had died prematurely.

After Southend School for Girls, Richardson, a woman of great natural intelligence, was unable for financial reasons to go to university, something that she regretted for the rest of her life. In 1945 she joined the Labour Party and was chosen as the organising secretary of the Keep Left group which was formed in 1946 to make sure that the Attlee government did not drift to the right in the way of Ramsay MacDonald. She held the position for three decades after the Keep Left and Bevanite groups had metamorphosed into the Tribune Group.

Those who worked with her could be certain that if she promised to do something or see somebody she would do so. In the brief period during which I served on the National Executive Committee of the Labour Party, I was, like others, deeply impressed by her committee and sub-committee skills and also by the way in which she really cared about members of staff.

In 1951 Richardson was elected to Hornsey Borough Council and became the full-time secretary and working partner of Ian Mikardo in his business which involved trade with eastern Europe. As a councillor and later as an MP she championed women: "I am not all that interested in the high-achieving woman... I'm concerned about all the women with expertise and wisdom, who never get to first base; they're poor, they've got kids... their lives are drudgery." The basis of Richardson's feminism was among the poorer women of her council ward, and later her constituency of Barking, who chose her from a powerful list of candidates to succeed Tom Driberg in February 1974. She had previously contested Harrow East against Commander Anthony Courtney in 1964.

Her parliamentary initiatives were coherent and legion. In her maiden speech she supported better pay for primary teachers and nursery teachers. She wanted the nationalisation of banks and insurance companies. She sponsored various domestic violence acts to aid battered wives. In November 1978 she led the Tribune Group delegation which drove Jim Callaghan as Prime Minister to apoplexy by proposing to vote against the 5-per-cent ceiling on pay increases in December 1978.

In all the Labour Party's internal controversies Richardson was at the epicentre, forever urging more political accountability. She warned against backsliding on mandatory reselection. She urged suspension of a Labour leadership election until a new system was in place in October 1980. But for all her internal party activity she found time to introduce the non-contributory invalidity pension bill to end discrimination against women in July 1981. She was Chairman of the Labour Party Conference at Blackpool in 1990.

Richardson was a champion of women's right to choose. She moved the key amendment to the Alton Bill reducing the abortion ceiling to 26 weeks in 1988, and she helped to defeat Ann Widdecombe's abortion-curbing Bill in January 1989.

Richardson was deeply interested in international causes and opposed the Falklands War, but perhaps her most important work was as the chairperson of the Black and Asian advisory committee of the Labour Party. To the pleasure of many of her colleagues and her trade union, the ASTMS (now MSF), she was made Labour spokesperson on women's rights on the front bench. Had she been in good health and had there been a Labour government she would quite certainly have been the first Minister for Women's Affairs in Britain. Alas that honourable ambition was not to be.

Jo Richardson's memorial is the intense loyalty and affection of many in the Labour movement, not only women, and particularly of those whom she by her example and seriousness of purpose attracted to politics. Gnarled with arthritis, scarcely able to move, devoid of self-pity, Jo Richardson made her last appearances in the Commons determined to record her vote come what may on occasions that mattered. It was symptomatic of one of her lifelong qualities: guts.

Much of Richardson's time in the following twenty years of representing Barking was engaged in persuading the Labour Party to take women's issues seriously. She was Labour's front bench spokesperson on women's rights from 1983, and in 1986 was finally able to persuade the party to adopt the creation of a ministry for women as policy. She played a leading part in campaigns in favour of abortion as a right, and for strengthening the law relating to domestic violence. Ever a ‘conscience of the party’, she was a leading member of the Campaign for Nuclear Disarmament and opposed the Falklands War. In the 1970s she was active in the campaign to make the leadership of the Labour Party more accountable to its members, and she backed Tony Benn's challenge for the deputy leadership of the party in 1981. She also supported a leadership challenge in 1983, but in 1988 left the Campaign Group amid some bitterness when it again backed Benn as a leadership candidate. She chaired the Labour Party conference in 1990, a performance notable for her refusal to call Tony Benn to speak against the Gulf War. Now she was no friend of the left nor sufficiently trusted by the right; she had lost her power base, and with it lost her seat on the national executive in 1991 (after twelve years of tenure) and on the shadow cabinet in 1992.

These were hard years: the decline in Richardson's political fortunes coincided with the illness and death, in 1993, of Ian Mikardo and a severe deterioration in the rheumatoid arthritis with which she was afflicted and for which she had a major spinal operation in 1993. Until the end of her life she continued to vote from a wheelchair in the House of Commons, arriving sometimes by ambulance, and was prominent in campaigning against the closure of St Bartholomew's Hospital, where she was being treated. She died, of respiratory failure, on 1 February 1994 at her home, 345 Latymer Court, Hammersmith Road, London.