EU Competition Commissioner, Margrethe Vestager is due to announce tomorrow that tax rulings issued to Starbucks by the Netherlands and to Fiat by Luxembourg, amounted to illegal state aid, according to reports in The Financial Times today.

It’s believed the decision could signal a similar outcome in the Commission’s investigation of alleged State Aid for Apple arising from its tax arrangements in Ireland.

According to the report, Holland and Luxembourg will probably receive detailed descriptions from the Commission telling them how to calculate the uncollected taxes, rather than a precise amount.

The case against Ireland and Apple was launched in June last year and alleges that Ireland gave selective tax advantages to Apple in two deals struck in 1991 and 2007, relating to transfer pricing and cost write-offs.

Ireland could be directed to recoup under-collection of taxes for the past ten years, which Apple has already indirectly confirmed could amount to more than $2.5bn.

Throughout the investigation a number of Irish politicians have insisted that the country does not have a case to answer.

Ireland has also signalled it will appeal any adverse judgement to the European Court of Justice.

Nicholas Shaxson, the author of Treasure Islands: Tax Havens and the Men Who Stole the World recently discussed the notion of competing through corporate tax policies on the Moncrieff Show, he argues that countries can't really use tax incentives to attract businesses.