Victims of contaminated blood in Northern Ireland are still not being treated equally to those in the rest of the UK, campaigners alleged.
Those who will benefit from a special scheme announced last month were diagnosed with Hepatitis C or HIV after receiving NHS-supplied infected blood.
The Department of Health said it can give a “firm” assurance that the £1 million allocated will be spent in full on support for victims of contaminated blood.
Families and Friends of Haemphilia NI has written to Prime Minister Boris Johnson calling for swift intervention.
In a statement it said: “This decision is affecting those in a vulnerable community in the most deprived area of the UK who are already suffering not just from the medical decisions in the past but the physical and mental impact of the revelations of the current inquiry.”
Last month, the group met finance minister Conor Murphy, who told them he was releasing £1 million to Stormont’s health department.
Part of the money is being quickly released as an interim measure to provide help while part of it will be held until more work can be done on how best to spend it.
The support organisation said: “Naturally we were pleased that this was a step in the right direction towards parity with England.
“Astonishingly, the Department of Health then announced a vague but different scheme.”
The money allocated by the Executive as part of the in-year budgetary monitoring process was intended to address an imbalance in support offered in other UK regions.
Thousands of patients across the UK were infected with HIV and hepatitis C through contaminated blood products in the 1970s and 1980s. Around 2,400 people died.
In April last year, at the outset of a state inquiry into the scandal, the Government announced an uplift in the level of financial support offered to those impacted during the time-frame of the inquiry.
However, that move only affected victims in England, with the devolved regions handed responsibility for making their own decisions on support. In Northern Ireland, the issue was one of many put on the long finger as a result of the powersharing impasse.
A commitment to resolve the issue was made in the deal that restored powersharing earlier this month.
The £1 million announced last month was to fund interim payments for Northern Ireland beneficiaries of the Infected Blood Payment Scheme ranging between £4,000 and £8,000 per person, depending on individual circumstances.
A statement from the Health Department said a large proportion of the money will fund the interim payments announced by Minister Robin Swann on January 27.
“The remainder will be allocated before the end of the financial year.
“The Department has been reviewing the Northern Ireland support scheme, with a view to ensuring arrangements best meet the needs of victims here.
“Some further work in relation to this review is required ahead of the rest of the £1 million being allocated.
“The financial year has under two months left, so this work will clearly be concluded promptly.
“Wider UK-wide discussions are continuing on greater parity of support right across the different UK support schemes.
“While the additional £1 million is very welcome, a non-recurrent allocation of temporary funding towards the end of the financial year is not by itself sufficient to resolve all the issues sustainably.”
The minister will be meeting shortly with groups representing victims to update them.