SPRINGFIELD, Ill. (AP) — Illinois Governor Bruce Rauner’s administration says it needs up to two more months to produce a plan to provide three years’ back pay to union workers.

A lawyer for the Republican governor told the Illinois State Labor Relations Board in a letter Monday that determining how much is owed to 20,000 workers is onerous.

Monday was the labor board deadline on the issue involving so-called step increases shut off in July 2015.

The letter says transferring money from other funds could jeopardize feeding prison inmates, providing utilities to the poor or medical care at state facilities.

Rauner stopped step increases while negotiating a new contract with the American Federation of State, County and Municipal Employees Council 31. There’s still no deal.

AFSCME officials say the union is determining a response.