Water rates are expected to be introduced in 2006

It is thought costs could be as high as �400 a year when charging is introduced.

The charges are expected to begin in April 2006, bringing Northern Ireland into line with the rest of the UK.

The General Consumer Council's Eleanor Gill said she was calling on the government to promise that poorer households will not face expensive bills.

We have an opportunity to show the rest of the world that we are looking after the people who can least afford to pay Eleanor Gill General Consumer Council

"We'd like a commitment from the government that they are going to protect vulnerable consumers," she said.

"We want them to ensure that we don't end up with the same situation as in England and Wales, where one in five households are in debt to their water company."

She said this showed that the charging system did not work.

"We have an opportunity to show the rest of the world that we are looking after the people who can least afford to pay," she added.