Margaret McDonagh, Labour’s first female general secretary, has been hailed as a “tour de force” and an essential part of the team that secured the 1997 landslide election victory for the party, after it was announced that she had died at the age of 61. Baroness McDonagh, who was elevated to the House of Lords in 2004, was, in effect, Peter Mandelson’s deputy during the 1997 election and went on to oversee a second dominant campaign in 2001. She became the party’s general secretary in 1998. She had been diagnosed with brain cancer in 2021. Sir Tony Blair described her as “an amazing, vibrant, unstoppable force of nature”, as well as a “vital element of New Labour”. Mandelson said she was a formidable figure who played a central part in constructing and maintaining the New Labour project. “Margaret was a tour de force,” said Mandelson. “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.” Labour leader Sir Keir Starmer said her death was “absolutely devastating” and praised her role in the party’s electoral successes. “Margaret may not have been as famous as some of the politicians she worked with but they wouldn’t have got into power without her,” he said. “Both inside and outside of the Labour party, Margaret was a tireless champion for women, mentoring a whole generation of political and business leaders.” Former Labour leader Neil Kinnock described McDonagh as “magnificent in every way”. He said: “She strove in the most practical ways for true equality for women throughout her life, she was a brilliant organiser for democracy and she had a mixture of steel and charm which earned her loyalty from friends and admiration from foes. Her courage in fighting her illness was remarkable, but typical of the valour which defined her.” McDonagh had been diagnosed with glioblastoma, a type of brain cancer. In an emotional speech in March this year, her sister Siobhain, the Labour MP for Mitcham and Morden, said the NHS needed to do more for sufferers of the condition. “It is not that there are a few trials – there are no trials, and there is nowhere to go,” she said.