Plans to reform the Water Service have proved controversial

Social Development Minister John Spellar insisted a plan to base the water charges on the value of property was the fairest method of assessment.

However, the Democratic Unionists and Ulster Unionists said the charges would mean financial hardship for many people in Northern Ireland.

There has been widespread opposition to the introduction of the charges.

During the debate on Wednesday, Mr Spellar said metering would benefit the wealthy.

Better-off households would effectively receive a subsidy from the less well off because 80% of the cost of water services stemmed from delivery of the service rather than the actual amount of water used, he said.

Mr Spellar said he believed the government had taken the right decision.

The introduction of water charging was necessary to deliver a proper water service to Northern Ireland over the next 20 years when 200,000 new homes would be built, he told MPs during Wednesday's debate.

'Freezing regional rates'

Earlier, the DUP's Peter Robinson, who secured the debate, warned that the introduction of water charges would mean one in four households in Northern Ireland facing financial hardship.

He said it was wrong for the government to press ahead with proposals which would mean people "paying twice for their water".

Mr Robinson urged ministers to reconsider alternative plans put forward by his party before Christmas which would include freezing regional rates and phasing in water charges over three years.

Ulster Unionist MP David Burnside said it was unfair to expect people in Northern Ireland "to pay for years of underinvestment" and he called for the option of metering be examined again.

Last month, a series of rallies took place across Northern Ireland in protest at plans to introduce water charges.

Water Service workers staged a one-day strike in February over the proposals to reform the service.

Plans for the government company to take over from the existing Water Service could see up to 700 jobs lost.