On 17 September, in the Seventh Chamber of the General Court of the European Union in Luxembourg, a legal case got under way that has a big impact on Ireland, Apple and other large corporations operating in Europe. 

In 2016, the European Commission ruled that more than $14 billion in undue tax benefits were granted to Apple by the Irish state. This is classified as illegal under EU state aid rules because it allowed Apple to pay less tax than other businesses. 

Ireland was ordered to recover the legal aid, plus interest, by the European Commission. But this finding is being appealed by both Ireland and Apple, which employs 6,000 people in Cork. 

The investigation was initially launched in 2014 and after two years, it concluded that two Irish tax rulings, in 1991 and 2007, artificially reduced Apple's tax liabilities in the country by accepting Apple's own accounting systems to calculate its profits.

The corporate tax rate that Apple paid in Ireland declined from 1 percent in 2003 to 0.005 percent in 2014. 

Apple counters that it is the world's biggest taxpayer and that the Commission has incorrectly attributed almost all the company's profits to its Irish operations. It says the Commission is trying to retrospectively change the legal tax framework it was operating under.

Ireland does not want to collect the $14 billion in back taxes. Foreign investment from international firms encouraged by its tax system has been a major driver of growth and employment in the country.