Any investigation by the European Parliament into "sweetheart" tax deals between multinationals and member states should not be a "witch hunt" against individual countries like Ireland, according to Fine Gael MEP Brian Hayes.

Mr Hayes has said that the centre-right grouping in the European Parliament will insist that any investigation will not be country-specific.

"If a Committee of Inquiry is to go ahead, the terms of reference must be fair and balanced. This cannot be a witch hunt against some member states - tax rulings in all member states must be investigated fully to identify any unfair tax advantages," he said.

Yesterday the parliament took the surprise decision to launch an investigation into so-called tax rulings for multinationals which have been criticised as offering preferential tax treatment.

The move is part of the fallout of the "Luxleaks" scandal in which dozens of high profile multinationals appeared to avail of lucrative and complex tax-avoidance schemes via the Grand Duchy of Luxembourg.

The move has the potential to keep the spotlight on Ireland's corporate tax arrangements with multinationals like Apple, Google and Facebook.

The European Parliament inquiry was triggered when 189 MEPs signed a motion in Strasbourg yesterday.

That number was enough to start an inquiry rolling.

It is now up to a body known as the Conference of Presidents, which includes the parliament President Martin Schulz and vice-presidents from the other political groupings, to set up the terms of reference.

There are already a number of investigations into Ireland's tax arrangements.  

Any further probing would be uncomfortable for the Government.

The European Commission is currently investigating two tax deals struck between Ireland and Apple in 1991 and 2007.

Brussels argues that the arrangements were preferential and amounted to illegal state aid to the US tech giant.

The Irish Government has strenuously denied the claims and will challenge any negative finding at the European Court of Justice.

Parallel to the Commission probe, the Economic and Monetary Affairs Committee of the European Parliament had also embarked on an inquiry into tax rulings, or letters of comfort, in Ireland, the Netherlands and Luxembourg.

The Committee was expected to draw up a report into the issue by June.

Mr Hayes said he expected that a visit by committee members to Dublin scheduled for 16 February would not now go ahead as it would be eclipsed by the forthcoming parliamentary inquiry.

The Conference of Presidents met this morning to discuss yesterday's vote.

They will meet again on 5 February at which they are expected to agree the terms of reference for the inquiry, which will have to be approved by a full plenary of the parliament in February.

Mr Hayes has said that the European Peoples Party (EPP) will adopt a stance in the negotiations that any inquiry should not be country specific but should take a "general" approach to the issues surrounding tax rulings.

However, the EPP has been divided over the issue.

During yesterday's motion, put forward by the Greens, a total of 20 EPP members voted against the party line and supported the motion.

Of the 20 MEPs, it's understood that 17 were German.

Parliamentary investigations are rare, and their findings have persuasive rather than legal force.

MEPs who supported yesterday's motion said that public pressure was building over the question of multinational companies and allegations of tax avoidance and evasion.

To date Ireland, the Netherlands and Luxembourg have been most in the spotlight over tax rulings.

However, before Christmas the new EU Competition Commissioner Margrethe Westager announced that the Commission would be investigating tax rulings in all member states, not just Ireland, Netherlands and Luxembourg.

Any investigation by the European Parliament would run parallel to the Commission's inquiry and would not be able to influence it, said Mr Hayes.