The New Zealand arm of Greenpeace is appealing a decision by the country’s High Court that blocks the environmental group from seeking to register as a charity, the New Zealand Herald reports.

The court ruled in May 2011 that Greenpeace’s protests and advocacy were political rather than charitable in nature, upholding a prior decision by New Zealand’s now-defunct Charities Commission.

Greenpeace contends the High Court relied on an outdated interpretation of the country’s law on nonprofit groups. The case is slated to be heard today by an appeals court in Wellington, New Zealand.

The appeal “raises the question whether New Zealand’s charities law will be in line with the Australian law, which allows charities freedom of expression in political debate as long as it is consistent with their charitable purposes,” said Bunny McDiarmid, executive director of Greenpeace of New Zealand.