The Irish embassy to the Holy See offered to act as an "intermediary" between the Murphy commission and the Vatican as a major diplomatic row intensified, but neither side took up the offer, it has emerged.

As the government braces itself for the imminent release by WikiLeaks of hundreds more US diplomatic cables that refer to Ireland, a confidential US embassy cable released by the Wiki­Leaks website also reveals that the Irish ambassador to the Vatican and former ambassador to the USA, Noel Fahey, described the row between the commission and the Vatican as the "most difficult crisis he had ever managed".

WikiLeaks is believed to have around another 900 cables emanating from the US embassy in Dublin, with 300 or so more from the US consulate in Belfast. It is expected to release these in the coming months, as it works its way through more than 250,000 such cables which it has obtained.

A spokesman for the Department of Foreign Affairs yesterday said it had no comment on the content of the cable.

Dated 26 February 2010 and noted as having been "contributed to and cleared" by the US embassy in Dublin, it outlines how the Irish government "wanted to be seen as cooperating with the investigation because its education department was implicated, but did not want to insist that the Vatican answer the requests because they had come outside of regular channels.

"The Irish embassy to the Holy See offered to facilitate better communications between the Irish commission and the Holy See, but neither party took any further action," it stated. "In the end, the Irish government decided not to press the Vatican to reply, according to Fahey's deputy…. (she said) the Congregation for the Doctrine of the Faith probably did not have much to add to the inquiry."

Commenting on the WikiLeaks revelations yesterday, Maeve Lewis of the One in Four charity revealed that she has yet to receive "even an acknowledgement" from the pope after her organisation wrote directly to him about the issue last February. This is despite that they had used proper diplomatic channels to do so. But the US diplomatic cables "simply confirmed what we already knew," she said.

"We have always said it was shameful for the Vatican not to cooperate with the Murphy commission, as is its ongoing refusal to divulge the contents of Congregation for the Doctrine of the Faith documents in relation to clerical sex abuse worldwide," she added.

Requests for information from the Murphy commission "offended many in the Vatican" who felt the government had "failed to respect and protect Vatican sovereignty during the (commission) investigations", the cable also reports.

Elsewhere, it claimed Vatican officials also believed Irish opposition politicians were making "political hay" from the situation by publicly urging the government to demand a reply from the Vatican following publication of the Murphy report in November 2009.