Thousands of public servants are at risk of losing their jobs on February 24, according to the public sector union, under new rules that prevent temporary employees from working for more than four years with the same government agency.

The Public Service Association raised concerns about the new rules on Tuesday at a joint parliamentary committee hearing into bullying within the safety regulator, WorkCover.

"It could affect up to 7000 full-time equivalent positions": Steve Turner.

A government spokesman said the claims by the union were a part of a Labor and union scare campaign and that public sector agencies were involved in active negotiations with unions and employees regarding the status of every employee with a view to making more of them permanent.

PSA assistant general secretary Steve Turner said there were 43,976 temporary employees in the public sector. Of those full-time equivalents, up to a half have been working for more than four years. Those unable to secure full time employment or a job with another agency would be at risk of losing their job.