Chancellor Jeremy Hunt will be questioned over the long delays to paying compensation to the victims of the contaminated blood scandal as he appears before the official inquiry.
Campaigners hope the former health secretary will commit to setting aside the funds to compensate the thousands affected by the scandal dating back decades.
Mr Hunt will be quizzed at the Infected Blood Inquiry on Friday afternoon after Rishi Sunak was heckled and laughed at when insisting they were working quickly to deliver the payments.
The Prime Minister’s claim they were working “at pace” to set up a scheme faced particular derision from those watching the proceedings in central London earlier this week.
Thousands died in what is widely recognised as the worst treatment disaster in the history of the NHS after being given contaminated blood products in the 1970s and 1980s.
Campaigners from Factor 8 said they want Mr Hunt to agree to allocate the funds to establish the recommended compensation scheme.
They also want the Chancellor to agree to interim payments for those who have not received them under emergency measures as victims continue to die at a rate of one every four days.
“We hope tomorrow’s evidence will finally lead to tangible progress towards justice,” the group said.
In 2017 the inquiry was set up to investigate how thousands of patients in the UK developed HIV and hepatitis C through contaminated blood products.
About 2,900 people have since died.
Many had the blood-clotting disorder haemophilia and were given injections of the US product Factor VIII.
Under an initial scheme, only victims themselves or bereaved partners can receive an interim payment of around £100,000.
But victims and their relatives have demanded swifter action as the Government says it will wait until the conclusion of the inquiry in the autumn before setting out further details.