Irish Water say payment rates to the utility are in line with what they were expected to be.

It has confirmed that less than half of Irish households have paid their first water bills, at 46%.

It says that 675,000 households are paying their water charges, which translates to about 2 million people that have paid the charge.

The company collected €30.5m of the almost €67m it had issued in bills in the first three months of the year.

Irish Water says customer engagement was high during that time, with 540,000 calls made to its helpline.

Opponents of the water charge claim the figures show their campaign is working.

Elizabeth Arnett is a spokesperson for Irish Water.

"It's a solid start and it's one from which we now move forward into bill cycle two", she told Newstalk Breakfast.

"It is in line with what we expected it to be...We're probably missing about 5% of houses that we haven't actually even sent a bill to".

"In terms of the amount we've billed out versus what we've collected, we're over half way there," she said.

"We know from utility experience that the second bill is a reminder in itself, and we've started the second bill process".

She also confirmed that extra charges will only apply by billing cycle five.

And it has also been confirmed that once people have registered - whether or not they have paid - they are entitled to the €100 water conservation grant.

The utility also says it is "fully funded" for 2015.

Listen to the interview below.