People bereaved in public tragedies must have an advocate to ensure that the "injustice heaped on injustice" the Hillsborough disaster families suffered is not repeated, Theresa May has said.
It follows renewed calls for a Hillsborough Law to ensure fairer treatment for bereaved families.
The former prime minister said the new law would be a "valuable legacy" for the 97 Liverpool fans who died.
This was echoed by Gordon Brown, who called for "no delays and no excuses".
The 97 Liverpool fans died as a result of the crush at the FA Cup semi-final match at Sheffield Wednesday's ground on 15 April 1989.