The European Commission has launched an appeal against a decision to overturn an order for Apple to pay back €13bn (£11.8bn) in alleged state aid to Ireland.
In July, Europe’s second highest court ruled that it was wrong to declare that Apple had received a “selective economic advantage” in a sweetheart tax deal with the Irish government.
Margrethe Vestager, the commission’s vice-president of competition policy, had led a six-year long investigation into the tech giant’s operations in Ireland and alleged that the iPhone-maker had effectively paid less than 1pc in corporate taxes.
The General Court's decision earlier in the year was a hammer blow to Ms Vestager who has taken a hard line against Big Tech. The case will now appear before the European Court of Justice, with a decision expected no earlier than 2021.
“The General Court judgment raises important legal issues that are of relevance to the commission in its application of State aid rules to tax planning cases,” Ms Vestager said in a statement.
“The commission also respectfully considers that in its judgment the General Court has made a number of errors of law.”
Ensuring all companies pay their fair share of tax remains a “top priority”, the commission said.
Ms Vestager claims that Ireland allowed Apple to avoid paying taxes on EU revenues between 2003 and 2014 by attributing almost all its EU earnings to an Irish head office, which it claimed existed only on paper.
The iPhone-maker and Ireland have previously challenged the Ms Vestager's order, which Apple CEO Tim Cook slammed at the time as "total political crap".
Apple said that the court's decision in the summer "categorically annulled" the commission's case and that the facts "have not changed since then".
"This case has never been about how much tax we pay, rather where we are required to pay it," Apple said in the statement.
"We will review the Commission’s appeal when we receive it, however it will not alter the factual conclusions of the General Court, which prove that we have always abided by the law in Ireland, as we do everywhere we operate.”
The commission, the EU’s executive arm, has already had to re-investigate some 40 probes following court decisions that picked apart its findings.
That includes a case in which Ms Vestager accused Starbucks of owing €30m in back taxes to the Netherlands.