The deadline for people to apply for the so-called water conservation grant has been extended by two weeks.

More than 500,000 people eligible for the €100 grant had yet to apply to the Department of Social Protection with just eight hours to go before the deadline of midnight on Thursday prompting the Government to extend until October 22nd.

The Minister for the Environment Alan Kelly and the Tánaiste and Minister for Social Protection Joan Burton made the announcement because of the “high volume of calls and applications [on Thursday] and issues that arose concerning the postal delays earlier this week”.

"The last few days have seen a very high number of applications for the Water Conservation Grant, " Mr Kelly said. "Water conservation is one of the Government's main objectives in reforming the public water system and I am keen to facilitate as many applications as possible for this conservation grant."

He urged all households who have not applied, whether they are Irish Water customers or not, but believe they are eligible for the grant, to apply as soon as possible “and to avoid leaving it to the last minute.”

Irish Water said it has seen the volume of calls to its call centre jump by 1000 per cent as the deadline loomed.

The utility apologised for the delays in answering calls and asked anyone calling in connection with the grant to contact the Department of Social Protection directly

A spokeswoman said the “only reason customers would need to contact Irish Water in relation to the Water Conservation Grant is to find out their Irish Water account number”.

She said account numbers could be found on the top right of Irish Water bills or alternatively customers already using online account management could also log on to their Irish Water account to find the number.

The Department of Social Protection helpline can be contacted at 0761-087-890, 021-206-5880 and 1890-100-043.

Details in relation to application for the Grant are available on watergrant.ie.