Andy Burnham, Sir Keir’s expected successor, said the debate will be a “deeply moving moment”. Both men are expected to speak in the Commons later.
The proposed law takes its name from the 1989 Hillsborough disaster, which claimed 97 lives after a crush during the FA Cup semi-final between Liverpool and Nottingham Forest at Sheffield Wednesday’s ground.
Police leaders were found to have spread false narratives about the disaster, blaming Liverpool fans, and withheld evidence of their own failings.
The legislation, which also commits to providing legal aid for victims of disasters or state-related deaths, was a pledge in Labour’s 2024 general election manifesto. It is formally known as the Public Office (Accountability) Bill.
Sir Keir had promised to pass the bill by 15 April 2025, to mark the 36th anniversary of the Hillsborough disaster.
But this deadline was missed and the government abandoned a final debate in January following a backlash from campaigners and some Labour MPs.
This came after a government amendment would have made co-operation with inquiries by intelligence officers subject to the approval of the head of their service.
Bereaved families said MI5 and MI6 officers should be fully subject to the proposed law and pointed to a series of cases where MI5 has provided false information, including the 2017 Manchester Arena bombing.
The government has now tabled amendments to the bill, with Justice Minister Catherine Atkinson saying they had listened to experts, campaigners, MPs and peers.
Atkinson said the amendments would ensure the duty of candour “applies to all individual intelligence officers while establishing secure procedures for the disclosure of sensitive information”.
Atkinson told the Commons that intelligence employees who receive a request for protected information would be required to send it to the head of their organisation and not directly to an inquiry or investigation.
The head of the intelligence organisation would then be responsible for sharing the information with public investigators.
Conservative shadow justice secretary Nick Timothy said he believed everyone agreed on the need for accountability but described the late introduction of the amendments as a “shambles”.
He said the government had made “contradictory promises” to the campaigners for this law and to the intelligence agencies, adding ministers “now pretend there’s no problem”.
Timothy said Sir Keir was “desperate for a legacy and to claim the credit” before Burnham takes over, adding: “The government has watered down the protections specifically proposed back in January for MI5, MI6 and GCHQ.”
The amendments are being considered during the bill’s report stage ahead of it being approved at third reading on Tuesday.
The bill will then proceed to the House of Lords where it could be changed further, including by any peers concerned over the impact of the bill on national security.
On Tuesday, Downing Street said the government wants the law to be on the statute book by April next year, in time for the next anniversary.
Ahead of the debate, Sir Keir said the “landmark law” was “a tribute to the incredible families and campaigners who have spent decades and decades fighting to get justice for their loved ones”.
“They suffered unimaginable grief and never gave up. If it wasn’t for their dedication the Hillsborough Law would never have happened,” he added.
During the debate on the bill in November last year, Sir Keir also highlighted that Hillsborough was not an isolated example of a state cover-up.
He raised failings connected to other scandals including the Grenfell Tower fire, infected blood and grooming gangs.
Burnham, who is on course to replace Sir Keir as prime minister on 20 July, said the Hillsborough families have “shown extraordinary courage” and they are “helping to reshape the relationship between the public and the state for generations to come”.
The Labour MP for Makerfield also said he believes there is a need to “build a Britain where every community is treated with equal respect and where, in the face of injustice, nobody walks alone”.
Hillsborough Law campaigners, including those whose family members were killed in the 1989 disaster, welcomed the return of the bill to the Commons.
In a statement, Charlotte Hennessy, Sue Roberts, Steve Kelly and Margaret Aspinall said: “This is not just about legislation, but about changing the way the bereaved and survivors are treated and a change in culture and it is deeply empowering knowing that this protects others forever.”