Gwyneth Dunwoody MP dies aged 77 after surgery

Gwyneth Dunwoody, the Labour veteran and "Mother of the House of Commons" as its longest serving female MP, has died suddenly at the age of 77.

Ms Dunwoody, an independent-minded thorn in the Government's side for the past decade, died after undergoing emergency heart surgery last week. Late last night, her son David said she had died, "peacefully in a gentle and calm way".

The maverick MP emerged as a hero of the Labour backbenches in 2001 after the Government tried to remove her as chair of the Transport Select Committee, a post she had held since Labour came to office in 1997.

After characteristically refusing to keep quiet – and instead touring the television studios to denounce the move – Labour MPs staged their biggest rebellion of the Parliament to have her reinstated.

Born in 1930 into impeccable leftist heritage – her father was Morgan Phillips, a Labour general secretary, and her grandmothers were suffragettes – Ms Dunwoody was elected to represent Exeter from 1966-70 and emerged as a leading figure on the party's "old right".

She joined the junior ranks of Harold Wilson's government of the late 1960s, but was only to experience front-bench status again during some of Labour's "wilderness years" in the 1980s as a battle-scarred opponent of the militant left.

Instead, as MP for Crewe and Nantwich since 1974, Ms Dunwoody mainly opted for a life on the backbenches and became best known for her fearlessness in the face of pressure from party whips to toe the line of the day. A constant advocate of enhanced powers for the Commons in the face of an over-mighty executive, she maintained scepticism towards political integration of the European Union on the ground of parliamentary sovereignty, a typically unfashionable position in modern Labour.

She infuriated New Labour in its first term with near-constant criticisms of transport policy from her powerful position of committee chairman (she insisted on the suffix). But she was admired by all sections of her party.

Last night, the Prime Minister, Gordon Brown, led tributes to the Labour veteran. He said: "She was always her own person. She was fiercely independent. She was politics at its best – a great parliamentarian. She will be sadly missed."

Tony Benn said Mrs Dunwoody "was listened to with great attention from the House itself".