Labour’s first female general secretary Margaret McDonagh, Baroness McDonagh, who was described as a “tour de force” for the party, has died at the age of 61.

Described as an “absolutely essential part” of Labour’s landslide election victory in 1997, the peer was diagnosed with a brain tumour after suffering from a series of fits in November 2021.

Her death comes after her elder sister Siobhain, a Labour MP for Mitcham and Morden, accused the NHS of “abandoning” her during an emotional speech in Parliament earlier this year.

Baroness McDonagh’s death was announced on Saturday.

Sir Keir Starmer said: “This is absolutely devastating news.

“Margaret McDonagh gave her life to the Labour Party. 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.