The Revenue Commissioners has played down fears over the workability of the crucial wage subsidy scheme aimed at keeping hundreds of thousands of people in employment.
Lawyers and businesses have expressed reservations about the scheme, which was rushed through the Oireachtas in the Covid-19 emergency measures bill.
But Revenue chairman Niall Cody described some commentary about the scheme as "unhelpful".
"I can ensure employers and interested groups our sole aim here is facilitate and support the employers," he told RTÉ Radio One.
More than 12,600 employers have registered for the scheme, which is intended to help employers retain staff for the duration of the crisis by paying a subsidy equal to up to 70pc of an employee's take-home pay, up to €410 a week.
Employers are encouraged to top-up their employees' wages to maintain them at their current level.
The scheme is available to employers who have lost a minimum of 25pc of turnover because of the Covid-19 crisis.
Among other issues, the Law Society's employment and equality law committee expressed concern at the subsidy payment being linked to the business's turnover.
In a letter to Social Protection Minister Regina O'Doherty on Thursday, it said this concept was broad, difficult to define and could include both domestic and non-domestic turnover.
The committee said the use of turnover also introduced uncertainty around the appropriate comparison period. But Mr Cody said employers would self-declare based on "a projection of likely reduction in turnover over for the next three months". He said the reduction could be based on the same period last year or a comparison with turnover in January and February.
Mr Cody said Revenue had published guidelines saying it will adopt a "reasonable, fair and pragmatic approach in considering whether the criteria have been met".