Revenue chairman Frank Daly warned accountants yesterday that tax officials were clamping down on what he called "aggressive tax avoidance". Dominic Coylereports.

Addressing a regulators' conference of the Institute of Chartered Accountants in Ireland (ICAI), Mr Daly said Revenue was "significantly ratcheting up" its anti-avoidance activity.

"As of today, we are actively challenging 46 avoidance schemes," he told the gathering of accountants and tax practitioners.

"You may take it that this area will be one of our key priorities in the coming years and that the numbers of challenges will increase. We will match aggressive avoidance with aggressive anti-avoidance interventions."

The Revenue chairman acknowledged the co-operation of tax practitioners in reducing tax evasion, congratulating ICAI members on the "responsible and effective contribution you have made towards reducing the levels of evasion in Ireland".

However, when it came to tax avoidance Mr Daly said that, "despite our generally good relationships, there is no great meeting of minds". He refused to go into definitions of what constituted unacceptable tax minimisation or aggressive tax planning but said he would address "fairness in the tax system".

He said defenders of aggressive tax planning argued that tax was simply a matter of law. "If it's legal, then it's ethical, they argue, and other values or morality are irrelevant." But he believed a growing majority believed such tax avoidance was unfair.

He suggested that, even if people did not agree with his argument, they should consider a more practical or strategic position. "Governments, who may judge that their capacity to deliver on carefully designed programmes is being undermined by artificial depression of their expected tax revenues . . . will, to put it bluntly, hit back."