The influential former secretary of the parliamentary Labour party (PLP), Alan Haworth, Lord Haworth, who has died aged 75, was one of the least publicly known yet most significant party figures over the past three decades. He was a close personal friend of two Labour leaders, John Smith and Tony Blair, but more importantly was responsible for restoring the lost political discipline among Labour MPs that proved vital in establishing the will to win the 1997 general election. A radical student and leftwing activist in his 20s, he became a Labour party pluralist who understood probably better than anyone the way the party worked – whatever the political discipline of any individual. What’s more, he knew its history and the rule book. This gave him an invaluable authority as the senior parliamentary backroom official, and meant that he was listened to – and heard – by the leadership as well as by independent-minded potential troublemakers on the backbenches. Haworth was widely respected and much valued throughout Labour’s ranks for the guidance he gave, particularly to new MPs, and for his facility in delivering a difficult message with warmth and wit. He joined the PLP office staff in the Commons’ cloisters in 1975 and was promoted to senior committee officer 10 years later. When Smith was elected leader after the party’s fourth consecutive election defeat in 1992 he appointed Haworth as PLP secretary; Haworth was thus poised to help Blair sweep to power two years later. Haworth was never a Blairite and used to say that his advice was rarely followed, but he did ensure that the party leader stuck to the rules on occasions when Blair wanted to ignore them. Blair habitually called him “Mon ami”. Haworth and his second wife, the lawyer Maggie Rae, who had once shared a flat with Blair’s wife, Cherie Booth, were responsible for secretly introducing the future prime minister to Diana, Princess of Wales, in January 1997, shortly before the general election. Rae was a member of the legal team at Mishcon de Reya, who had acted for the princess in her divorce proceedings, and she and Haworth set up a hush-hush dinner at their then home in Hackney, east London. The evening was a great success, with the princess “mucking in”, as she was later recorded saying by Alastair Campbell in his published diaries; intriguingly, Diana also told Rae afterwards, according to Campbell, that “she would like to help us if she could”. Campbell records Haworth himself saying: “Imagine a lad from Blackburn like me having his plate cleared away by Princess Diana.” Haworth was born in Blackburn, the only child of Hilma (nee Westhead) and John Haworth, who ran a grocery store. He was educated at Blackburn technical and grammar school and won a place to read medicine at St Andrews University, from which he dropped out after a year. He subsequently graduated in 1971 from Barking Regional College of Technology (part of North East London Polytechnic; now the University of East London) with a BSc in sociology, externally awarded by London University. He was president of the students’ union, became immersed in local radicalism and worked briefly on the administrative staff of the college. At the time an officer and activist in Newham North East Labour party, Haworth was a leading figure in a controversial and successful campaign to reveal the role of freemasonry in the activities and policies of the local council. He was also among those local party members who ended up in the high court as a result of their attempt to deselect the sitting Labour MP, Reg Prentice – who subsequently defected to the Conservative party and became a minister in the Margaret Thatcher government. The court case was thrown out, but events in Newham North East proved a catalyst for the bitterly divisive campaign for greater party democracy that would keep Labour out of office for a generation. Haworth joined the House of Lords in 2004. In the Commons he had entered into a “non-aggression pact” – not to use information they had learned by mistake – with his near namesake, the former Tory MP Alan Howarth, who had defected to Labour in 1995. The confusion continued, however, when Howarth became a peer as Lord Howarth of Newport in 2005. Haworth was a keen Labour historian and with his colleague, Dianne Hayter, in 2006 published Men Who Made Labour, a biography of the first 29 MPs elected for the Labour Representation Committee 100 years earlier. He was also an avid rock fan. But his main leisure pastime was revealed by the maps of Scotland and the Pyrenees on the wall of his PLP office, where he plotted future hill walks. In “term time” he led a Radical Ramblers group on walks on the South Downs Way, the Essex coastal path or the Capital Ring. He started mountaineering during his year at university in Scotland and scaled a number of the 282 Munros, Scottish mountains of more than 3,000 feet. He became a Munro “bagger”, a pastime he shared with Smith, to whom he was proud to have taught “a few things” about safe hill-climbing. Despite suffering the after-effects of Lyme disease, in 2001 Haworth bagged his last Munro – on the centenary of the first such triumph – and went on to target the 226 Munro Tops, the nearby subsidiary peaks. He “compleated” (in the jargon) this target on 20 July this year, again the centenary of the first such achievement, with Meall Coire na Saobhaidhe, near Balmoral. His first marriage, to Gill Cole, ended in divorce. He is survived by Rae, whom he married in 1991. • Alan Robert Haworth, Lord Haworth, politician, born 26 April 1948; died 28 August 2023