THE joint Oireachtas Committee on Economic Regulatory Affairs has emerged as the most likely body to hold an inquiry into what caused the banking crisis, but the government may consider holding a referendum to give it powers to compel witnesses to attend.

Even before last month's intervention by Green Party leader John Gormley backing an inquiry, there was a private acceptance at ministerial level that such an investigation would be inevitable at some stage in 2010.

Gormley's comments caused some irritation within government, but ministers say that they "know it has to be done. The pressures are going to be too much."

And there is general agreement that if and when the inquiry does happen it should be carried out within Leinster House for cost reasons and because outsourcing it would show the Oireachtas in a bad light.

The Joint Committee on Economic Regulatory Affairs – rather than the Public Accounts Committee which carried out the Dirt inquiry a decade ago – is seen as the obvious body, doing its work alongside an independent financial expert who would first collect evidence and material.

The committee is chaired by Fianna Fáil TD Michael Moynihan and includes heavyweights such as Fine Gael's Leo Varadkar and Kieran O'Donnell, Labour's Seán Sherlock and independent senator and finance expert Shane Ross.

There is an acceptance across parties that any inquiry will examine the systematic banking failures rather than make adverse findings or conclusions against individuals.

Labour TD Pat Rabbitte is bringing forward legislation which he says will restore the rights of parliamentary committees to hold inquiries.

However, the view within government is that, if the inquiry is to have teeth, it will still be necessary to hold a referendum this year to compel witnesses to attend, following examples of previous witnesses to Oireachtas committees declining to do so.