Minister for Finance Michael Noonan met EU competition chief Margrethe Vestager yesterday in Brussels amid growing expectations that a ruling on the Apple tax case is imminent.

The meeting, which took place just 24 hours before US treasury secretary Jack Lew flies to Brussels for talks, was the first bilateral face-to-face meeting between Mr Noonan and the former Danish finance minister since she inherited the Apple case on becoming competition commissioner 18 months ago.

Mr Noonan is understood to have underlined the government’s position that the case against Apple, based on EU state aid law, is unfounded, as well as the government’s intention to fight the case at the European Court of Justice in the event of an adverse ruling.

A decision on the investigation, which began three years ago, is expected by the end of this month.

The EU’s anti-trust arm sought extra information from Irish tax authorities in March, delaying the outcome of the state-aid investigation.

That intervention followed the submission of additional information by the Revenue Commissioners to the commission in late January.

Mr Lew is expected to underline US opposition to Apple being obliged to pay any back taxes, which is emerging as the key point of tension between the two sides.

The meetings take place against the background of unprecedented tensions between Washington and Brussels over the commission’s clampdown on the tax practices of US multinationals.

In February Mr Lew wrote to European Commission president Jean-Claude Juncker, criticising the commission for unfairly targeting US companies.

Ms Vestager has denied accusations of bias against US companies.

In addition to the long-running Apple case, the commission's powerful anti-trust arm is also said to be preparing additional anti-trust charges against Google, accusing the computer giant of abusing its dominance of the search engine market to prioritise its own services.