No official from the Irish Congress of Trade Unions had complained about the concept of "individualisation" of taxation, according to the Minister for Finance.

Defending his controversial Budget taxation measures, Mr McCreevy said individualisation had been on the agenda of trade union members particularly since 1980, following the Murphy judgment on married couples' income tax. He denied that his Budget measures lacked balance "and I am still strongly of that view".

He told Opposition spokesmen during Finance questions that because of "perceived lack of balance between the single-income and double-income family" he brought forward measures planned for two subsequent budgets, to "address that perceived imbalance".

Labour's finance spokesman, Mr Derek McDowell, asked about the cost of completing the individualisation of the standard rate of income tax over two years.

He suggested that there was little scope for divergence from the Minister's strategy since individualisation would cost £839 million to complete, and about £0.5 billion to reduce tax rates as set out in the Government's programme.

Mr McDowell said the Minister was "stuck" with his strategy for the next two years "whatever might be agreed in the Partnership 2000 arrangements", and if he did not pursue this "his authority as Minister is greatly reduced".

Mr McCreevy said: "I would have thought it was a laudable objective to try to ensure that in two years and four months' time, 88 per cent of taxpayers would be paying tax at the standard rate which will then be 20 per cent. I set out clearly what I was going to do."

Pointing out that individualisation was on the trade union movement's agenda a long time, he said: "If the deputy can find a trade union leader who has spoken against individualisation, I will bow to his superior knowledge of the trade union movement, but I am not aware of one".

Fine Gael's finance spokesman, Mr Michael Noonan, asked what level of income, earned or unearned, the spouse at home would be allowed to have before the other spouse was disqualified from the £3,000 allowance.

The Minister said it would be a matter for the Finance Bill but pointed out that the allowance would be given to all stay-at-home carers for the handicapped, children or the elderly. "Income does not come into it."

Mr Noonan said it was "clear to me the Minister has not thought this out at all".