The National Party is continuing to work on restoring more than a dozen websites taken down in a cyber attack on Monday.
The group Anonymous New Zealand has claimed responsibility for hacking the sites of some National MPs and the party's environmental wing the BlueGreens.
It says it hacked into the sites as a protest against legislation that would allow the Government Communications Security Bureau to spy on New Zealanders.
Prime Minister John Key, whose website is one of those affected, was not impressed.
"Pretty juvenile behaviour in my view. these people are obviously doing something that's both illegal and inappropriate. They're trying to make their own political point, but their point's wrong."
Meanwhile on Twitter, internet entrepreneur Kim Dotcom has asked Anonymous New Zealand to stop the attack, saying hacking the National Party websites just gives John Key a new excuse to pass the GCSB amendment bill.
Justice Minister Judith Collins said the hacking of ministers' websites could be a case of cyber crime but would not expect any charges to be laid. When questioned by reporters at Parliament, Ms Collins said it is not a valid form of protest.
Deputy Prime Minister Bill English said the hacking shows why strong legislation is needed to protect infrastructure such as government websites.
Mr English said taking down a ministerial website does not matter that much, but it would be more serious if Inland Revenue or Work and Income were targeted.
In 2011, Anonymous New Zealand claimed to have shut down Parliament's website in protest at changes to copyright law, but the Parliamentary Service did not reveal the cause.
