Over 100,000 people have signed a petition calling for Hillsborough disaster Cabinet papers to be released.
This passes the threshold for a potential debate in parliament on the subject.
Ninety-six Liverpool fans died in the disaster on FA Cup semi-final day at Sheffield Wednesday's ground Hillsborough on 15 April 1989.
The issue has been at the centre of a 22-year campaign by Liverpool supporters.
The success of attaining 100,000 signatures will increase pressure on the Cabinet Office, especially as it follows on from a ruling by information commissioner Christopher Graham that the papers should be published.
However the Cabinet Office believes the Hillsborough Independent Panel, which was established under Labour, should oversee the release of documents.