Institutions refusing to join the national redress scheme are "doubling down" on the crime of child sexual abuse, Prime Minister Scott Morrison says.
Mr Morrison and Social Services Minister Anne Ruston have warned institutions they may lose funding and tax concessions if they fail to sign up by Tuesday's deadline and will be named and shamed.
"All institutions are doing in not joining is doubling down on the crime and doubling down on the hurt," they said in a letter to 25 institutions.
"We consider it to be reprehensible that you have failed to sign up to the scheme."
The Jehovah's Witnesses is among the organisations that has refused to sign up, arguing it does not have the institutional settings of other faith-based institutions that the redress scheme is designed to cover.
Senator Ruston is set to name the non-participating institutions on Wednesday, when she will announce what action the federal government will take against them.
"We urge you to join the scheme not because of concerns about being identified, but because it is the right thing to do," the minister and Mr Morrison said.
"It is the right thing to do by survivors and their families and it is what every, decent, honest, Australian demands."
The letter confirmed financial sanctions including the removal of charitable status and tax concessions were possible.
"Institutions that do not provide a clear statement of intent by 30 June 2020 will be publicly identified and the government is considering other actions including the appropriateness of future funding and tax status."
The letter was sent to 25 institutions on Friday, urging them to commit to join the scheme by Tuesday.
Those 25 institutions, which were either named in redress applications or the child abuse royal commission, are holding up claims from 103 survivors.
Legal service Knowmore's principal lawyer Anna Swain said survivors hoped institutions did the right thing, but expected some victims would miss out on compensation and acknowledgement.
"There will be many people who are left incredibly distressed and disappointed," Ms Swain told AAP.
Religious, community, charity, education and sporting organisations have had two years to opt in to the scheme.
Ms Swain said survivors wanted action against those that refused to join.
"They will still continue to fight and they want every possible action to be taken to try to hold these institutions accountable."
As of 12 June, the scheme had received 7133 applications and made 2501 payments totalling almost $202 million.
A further 623 redress offers are awaiting an applicant's decision.
