The arrival of the first bills from Irish Water could be delayed by up to one month if the Commission for Energy Regulation grants the company an extension to the sign-up period for customers.

Speaking at the Joint Oireachtas Committee on Environment today, CER commissioner Paul McGowan said a decision would be taken this week on extending the period people have to sign up for the water charges, which was supposed to close at the end of this month, by 30 days.

Mr McGowan said if granted, the extension to the “validation period” could impact on when the first water bills are issued, which was expected to be at the start of January but could now come up to four weeks later.

He made the comment after a question about the timing of the first bills from Labour TD Robert Dowds, who said facing bills in January would pose difficulties for many customers.

Asked about a potential delay to the issuing of bills, a spokeswoman for Irish Water said it was working to an October 31st deadline for customer sign-up and the billing plans remained unchanged for now.

Mr McGowan also said the CER, which set the price Irish Water will charge for water used, has not approved the call-out charges customers will face when leaks emerge or repairs are necessary.

Irish Water at the weekend said these would range from €188 to a €282 out-of-hours charge as well as €220 to test pressure and €17 for meter reading.

Mr McGowan said the commission had expressed concern about the level of these charges and said a further consultation would be carried out.

He said should anybody incur they would be rebated over and above what is ultimately approved.

The commission is appearing before the committee to discuss water charges.

Its representatives have declined to discuss the controversy surrounding salaries or bonuses at the semi-State firm, saying these were outside its remit.