Law died at his home in Nantyglo, aged 58, suffering from a recurrent brain tumour first diagnosed during the 2005 election campaign. As a result of his death, there were by-elections in Blaenau Gwent for both the UK Parliament and the Welsh Assembly seats. In the by-elections Law's former agent, Dai Davies, won the election to Law's former Westminster seat, while his widow Trish Law succeeded him in the Welsh Assembly. Both stood under the banner of the Blaenau Gwent People's Voice Group.