The deadline for applications to the Residential Institutions Redress Board (RIRB) is due to pass today.
The board placed advertisements last month saying it would not accept applications after today.
The RIRB was set up in 2002 to compensate persons who were abused as children while in industrial schools, reformatories and other State institutions.
The Taoiseach and Tánaiste have been urged to instruct the RIRB to extend its deadline for receipt of applications for compensation.
Christine Buckley of the Aislinn group said last week the deadline had not been sufficiently advertised. She called for a three-month extension of the deadline and an immediate campaign - using TV, radio, and outdoor advertising - to ensure no survivor missed out.
The cost to the State of the scheme is now expected to be in the region of €800 million. The average settlements is more than €70,000.
The board has been receiving more than 600 applications a month, bringing its total to date approximately 10,000. As of November 17th, it had dealt with 4,267 cases; made 3,154 offers following settlement talks; and 1,006 awards following hearings.
Five applicants rejected awards, while 17 applications resulted in no award. The largest award it made was €300,000.