Anti-piracy group BREIN is refusing to back down in its attempts to have The Pirate Bay blocked in the Netherlands. After a big legal defeat in January, the Hollywood-backed group is now taking its case against a pair of local ISPs all the way to the Supreme Court. Both intend to fight all the way.

Four years is a long time to fight over a website, but that’s exactly what Dutch anti-piracy group BREIN and pair of local ISPs have been doing since 2010.

The action began when BREIN targeted Ziggo, the Netherlands’ largest ISP, in an attempt to force it to block The Pirate Bay. Ziggo were later joined in the case by rival ISP XS4ALL, with the pair teaming up against the prospect of a bad precedent and an avalanche of additional blocking demands.

The case has taken numerous twists and turns, with a court first deciding that blocking all subscribers was a step too far. BREIN responded to this defeat by taking the case to a full trial, which it won. The ISPs refused to give in, filing subsequent appeals on the basis that any blockade would be ineffective and would deny subscribers free access to information.

In January the Court of The Hague sided with Ziggo and XS4ALL, leaving the ISPs to unblock The Pirate Bay, an action they took immediately.

BREIN limped away with no blockade and close to half a million dollars in legal fees, but one last legal avenue remained – taking the case to the Supreme Court. According to XS4ALL, on April 25 this year it was summoned by BREIN to defend itself in the Supreme Court.

A statement issued by the ISP explains that the appeal will not see the dispute resubmitted in its entirety and judged on its merits as is often the case. Instead, the Supreme Court will only overturn the decision from January if it finds that the Court of the Hague “erred in law” or failed to comply with procedural rules.

“The facts as determined by the Court are fixed, the case will not be materially redone and the Supreme Court itself will not perform an investigation. The claimant [BREIN] cannot bring more new facts, nor contest the facts. Only the legal criteria which the Court has applied will be questioned,” the ISP explains.

“If the appeal is successful and the judgement of the lower court is set aside, it may be sufficient to conclude the case. If a new examination of the facts is necessary, the Supreme Court will probably refer back the case to the Court for a full retrial,” XS4ALL adds.

XS4ALL now has until September 5 to submit a statement for its defense.