MP dies after being shot and stabbed in 'Britain First' attack
The 41-year-old mother of two was attacked at lunchtime in Birstall, West Yorkshire, near a library where she held advice surgeries.
Temporary chief constable for West Yorkshire Dee Collins told a news conference: "I am now very sad to have to report that she has died as a result of her injuries."
Labour leader Jeremy Corbyn said the country would be "in shock at the horrific murder" of the MP, who was a "much loved colleague".
The alleged gunman has been named locally as Tommy Mair, 52, who neighbours in Birstall have described as "a loner".