The apology, one of the headline recommendations of the four-year inquiry by Sir Anthony Hart which was completed in 2017, was scheduled to take place in Parliament Buildings on 11 March 2022.

Representatives of other state and religious institutions, found by the Hart inquiry to have been responsible for the abuse, were also due to provide statements of apology.

Jon McCourt, chairperson of Survivors North West, said: “This is such a betrayal. It has echoes of 2017 when the Executive collapsed the last time and survivors were abandoned with no-one in place to act on Sir Anthony Hart’s recommendations from the public inquiry.

“We have waited for more than five years for this public apology. In reality, we have waited a lifetime. Now, on the cusp of that official expression of sorrow, we are being disregarded once again.

“The promised apology needs to be delivered by the first and deputy first minister and not be seen as another casualty of political opportunism. We are calling for urgent discussions with The Executive Office to find a way forward that meets the expectations of victims and survivors of historical institutional abuse.”

Gerry McCann, chairperson of victims group Rosetta Trust, said: “Survivors of institutional child abuse in Northern Ireland have been let down time after time by political leaders. This is just the latest betrayal.

“We were assured by ministers just weeks ago that the public apology would be going ahead on March 11. Now it appears that those promises are worthless. We will be protesting in the strongest terms possible to those responsible.”

Patrick Corrigan, Northern Ireland director of Amnesty International UK, added: “Public apologies are an important part of reparation for harm suffered by victims of human rights abuses. To be meaningful, they must be delivered with due respect, dignity and sensitivity to victims.

“This unfolding debacle – with a long-delayed public apology, finally being promised and now expected to be cancelled – is the very opposite of this respectful approach and will add further trauma to good people who have already been let down so often.”