Baroness Glenys Kinnock died peacefully in her sleep on Sunday with her husband and former Labour Party leader Lord Kinnock by her side, her family said.
She served as a minister in Sir Tony Blair’s Labour government and also represented Wales in the European Parliament as an MEP.
Her family, which includes Labour MP Stephen Kinnock and daughter Rachel, said they were “devastated” by her death.
Labour leader Sir Keir Starmer called her a “true fighter” for the party as he paid tribute to her life and career.