THOUSANDS of gardaí, prison officers and other public servants have been hit with an income levy on money earned before the controversial tax was even introduced.

The Revenue Commissioners has confirmed that any money paid in 2009 will be subject to the 1% tax no matter when the work was carried out.

Staff who earn overtime or bonuses were worst affected as the Department of Finance took in at least an extra €1m in income levies.

The Revenue Commissioners had received dozens of queries from disgruntled workers who complained extra tax was being taken off them for work they had carried out last year – long before the introduction of the blanket levy.

A spokesman said: "We did have quite a number of enquiries particularly from the likes of gardaí and prison officers, who had worked overtime in December.

"Their pay claim did not go through until January and they found themselves subject to the levy. That is just the way these types of taxes work."

The Department of Finance confirmed that employers have to deduct the levy on all earnings from new year's day onwards.

A statement said: "The position is that, on the basis of the legislation as enacted, the employer is legally obliged to deduct income levy from all payments of emoluments [which would include salary, bonus payments and other payments in the nature of pay] made... on or after 1 January 2009 irrespective of the period to which the payments relate".