Fianna Fáil has warned it may not facilitate the election of a new Taoiseach as the dispute over water charges escalated.

In a letter to Fianna Fáil TDs and Senators, the party’s spokesman on housing Barry Cowen strongly criticised Fine Gael for allowing the impending leadership contest interfere with the Oireachtas committee examining the future of water charges.

Mr Cowen said the Minister for Housing Simon Coveney was directing the Fine Gael members of the committee and was engaging in aggressive briefing and statements.

The letter, which was sent from the party leader’s office, reads: “From the moment we signed the confidence and supply agreement we have operated in good faith. We disproved the empty commentaries that we would manoeuvre to bring down the government and have 100 per cent implemented both the spirit and letter of the agreement on water and every issue.

“We have had many problems with Fine Gael’s behaviour and have already signalled to Fine Gael our extreme annoyance at breeches to the spirit and letter of the agreement. However, the handling of water in recent weeks has brought this to a head.”

Fine Gael and Fianna Fail are at odds over the final report of the Oireachtas committee.

It provides for finanical penalties for those who excessively use water.

However, Fine Gael insists the absence of a charging regime and the abandoning of the metering programme will breach European law.

Mr Cowen said only the Government can legislate to implement the committee’s findings. The party has sought to escalate problems and has engaged with the media rather than with Fianna Fail, he adds.

Fine Gael has now acted in clear bad faith on a series of occasions and Mr Cowen said a breach of the confidence and supply agreement will have consequences. “Fine Gael faces a choice – it can either be constructive or it can go further along its destructive route.

“Both of the ministers campaigning for their party’s leadership would be well advised to understand that this behaviour means that Fianna Fáil will require full confirmation of Fine Gael’s intention to honour its commitments under the confidence and supply agreement before facilitating any potential changes to government personnel and roles.”

The confidence and supply agreement reached between Fianna Fail and Fine Gael states that the two parties can take varying views on the report’s findings.

However, it says the Government must facilitate the recommendations, as voted by the Dáil.

Mr Coveney has insisted he cannot bring forward or allow the passage of legislation that breaches Ireland’s commitments under EU law.

The dispute has been escalating over the past number of days.

The committee is due to meet on Tuesday to consider the final report and legal advice sought by Fine Gael.