The first female general secretary of Labour, Margaret McDonagh, passed away at the age of 61.
An “unstoppable force of nature” and a “tireless champion for women” were used to characterise the politician, who served as Baroness McDonagh in the House of Lords, during tributes on Saturday.
She was praised for playing a “absolutely essential” part in helping Labour win the 1997 general election, according to Sir Keir Starmer, the party’s leader.
“Margaret may not have been as well-known as some of the politicians she collaborated with, but they couldn’t have become leaders without her,” he continued.

“Both inside and outside of the Labour Party, Margaret was a tireless champion for women, mentoring a whole generation of political and business leaders.”
In an emotional House of Commons speech earlier this year, Siobhain McDonagh, the Labour MP for Mitcham and Morden, accused the NHS of “abandoning” Baroness McDonagh as she received treatment for brain cancer.
She fought back tears as she lambasted the NHS for the lack of advancement in brain cancer therapy since 2005 and revealed that her sister was undergoing treatment that required a monthly journey to Dusseldorf, Germany for four days.
Sir Keir added: “To the very end Margaret was campaigning for better healthcare for those with brain tumours.
“Margaret was absolute proof that one person can make a difference in the world. The difference with Margaret is that she also built an army of change-makers along the way who will proudly carry on that fight in her name.
“You can’t think about Margaret without her sister Siobhain (the Labour MP for Mitcham and Morden), campaigners together not just in Mitcham and Morden, but across the world.”
Former prime minister Sir Tony Blair said: “Margaret was an amazing, vibrant, unstoppable force of nature. Dedicated to the country, the Labour Party and to fighting for what she believed was right.
“As general secretary of the Labour Party she was an incredible support to me and a vital element of New Labour.
“Most of all she was the most loyal friend anyone could wish for.”
Lord Mandelson, who was Labour’s campaign director in the 1997 general election, said: “Margaret was a tour de force.
“She ran Millbank in 1997 with a rod of iron. Everyone was terrified, including me.
“I have never met anyone so resolute, so uncompromisingly honest and so direct.
“She almost never made it to the high command in the early 1990s, but once she arrived there was no going back. She was formidable.”
Shadow environment secretary Ed Miliband called Baroness McDonagh “an incredible woman, a huge fighter for social justice” in a speech at the Glastonbury Festival.
He told the PA news agency: “She deserves huge credit for Labour’s election victory in 1997 – for the country having been changed.
“Many people won’t know her name but she was someone who helped transform this country.
“She’s fought her illness with incredible courage and she will be really so sorely missed by everyone in the Labour Party and the Labour movement.”
Shadow chancellor Rachel Reeves told PA: “Margaret is just such a big figure in the Labour Party’s history. Her role in 1997 in that historic victory cannot not be underestimated.”