Kim Dotcom and Prime Minister John Key are set to go head to head on Wednesday when the internet mogul voices his opposition to the Government's controversial GCSB legislation at a parliamentary committee.
The Government last month proposed legislation reforming the Government Communications Security Bureau to allow for it to provide support for the New Zealand police, Defence Force and the Security Intelligence Service.
The Intelligence Security Committee will start hearing submissions on the legislation this week.
Dotcom today issued a challenge to the Prime Minister through Twitter, saying he would tell the Government why the GCSB legislation would not work.
"If you want to witness John Key and the #GCSB getting exposed join me in Parliament this Wednesday. It's a public hearing," Dotcom said on the social media site.
Mr Key today confirmed he would chair the committee. Act Party leader John Banks will also be in attendance.
The GCSB has been under scrutiny after it was revealed to have illegally spied on internet mogul Kim Dotcom because he was thought not to be a New Zealand resident.
The Government needs 61 votes to pass the Government Communications Security Bureau and Related Legislation Amendment Bill but is currently one vote short.
Mr Key needs independent MP Peter Dunne to vote for the bill to pass as it appears unlikely the Government's other support partner, the Maori Party, will back it.
If he cannot secure Mr Dunne's vote, Mr Key will be forced to go to New Zealand First for support.