From the wage subsidy scheme:
The subsidy scheme currently refunds employers up to a maximum of €410 for each qualifying employee. From 4 May it will change to a system based on the previous average take home pay of employees. See below for details.
The subsidy is based on an employee's pay after tax, USC and PRSI, not their gross pay.
Net pay would make more sense ....... bit of a pisser if you bought a new car for that Tax year to reduce Tax liabilities