Minister for Transport Leo Varadkar has said he believes a “large number” of people will pay the household charge by the March 31st deadline, but that of those who don’t, the “vast majority” will pay in the next six months to avoid fines.

Mr Varadkar said today a large number of people would pay in the next week or two.

“I am conscious that the majority of people will have paid it before the Exchequer returns have to be done at the end of the year,” he said. “I understand that there are a lot of people who object to the charge and people have the right to object to something if they don't agree with it.”

The Minister said he had paid his own €100 household charge in January.

He said people had a responsibility to obey the law. "You can't break the law one day and then expect the law to be there to protect you the next day," he said. “And you can't refuse to pay your taxes one day and expect then to be able to draw on other people's taxes when you need to avail of services the next day or later on in your life.”

Mr Varadkar said he was not aware of any option to extend the deadline for payment of the charge, but that this was a matter for Minister for the Environment Phil Hogan.

Late payment interest of 1 per cent per month, or part of a month, will apply to outstanding amounts after March 31st.

A late payment fee of 10 per cent will apply to charges paid no later than six months after the due date. If payment is made later than six months after the deadline but not later than 12 months, a 20 per cent late fee will apply. The fine increases to 30 per cent of the outstanding amount after that.

Fianna Fáil today called for an extension of the deadline, in light of what it said were “serious inadequacies with legislation, the lack of a proper information campaign and inequalities with payment procedures”.

The party’s environment spokesman Niall Collins said the Government had made “a mess” of the household charge from the beginning.

He said Mr Hogan had been “so distracted by rushing through his controversial legislation and scaring people into paying it by the end of March that he has completely abandoned all sense of fairness and procedure”.

Mr Collins cited a High Court challenge to the household charge on the basis that the legislation was not published in Irish.

He said there had been initial problems with some local authorities mistakenly charging an extra 10 per cent where householders sought to pay the charge directly in their local authority office.

In addition, the campaign had alienated thousands of older people and others who did not have internet access because it was based on an online model of registration.

Fianna Fail called for a proper information campaign, the extension of payment methods to include local post offices, and for exemptions for more vulnerable households.

Several trade unions today voiced their opposition to the €100 household charge.

Unite has urged its 60,000 members not register for the charge before the March 31st deadline.

“We have been urging and encouraging members to organise within their workplaces and local communities to stand in support of the campaign and push the Government towards a fairer and more equitable solution,” union spokesman Rob Hartnett said at a press conference today. The union is not opposed to a property tax but to the idea of a flat rate charge, he said.

The executive of the Civil and Public Service Union (CPSU) has passed a motion calling for the tax to be scrapped but has not called on members to boycott the charge.

The general feeling of members, which is made up of lower paid civil and public servants, was

that the lower paid are being "hit the hardest" once again, executive member Terry Kelleher said.

A motion calling for a ballot for industrial action if members have to deduct the charge from wages will be discussed at the union’s national conference next month.

Dublin Council of Trade Unions spokesman Des Derwin said the umbrella body supported the efforts of the Campaign Against Household and Water Taxes organisers “to support the efforts of organisers to encourage people not to register and not to pay”.

The meeting of unions was organised by the campaign, which will hold a protest rally in Dublin on Saturday.