United Future leader Peter Dunne says he will question government ministers about the real cause of Warner Bros' concerns over filming The Hobbit in New Zealand.

The Government cut a deal with the producers in October, changing employment law and giving the film studio an increased tax concession to secure the films. At the time, ministers said Warner was worried about industrial action by the union Actors' Equity.

But an email written by The Hobbit director Sir Peter Jackson, issued under the Official Information Act, showed union action had nothing to do with Warner's decision on whether the movies would be filmed here.

Mr Dunne voted for the urgent law change in Parliament, and said yesterday that it had been clearly indicated to him that "union issues" were a reason why the deal had to be made.

The email was sent to the office of Economic Development Minister Gerry Brownlee, a key figure in the negotiations.

Council of Trade Unions president Helen Kelly said the email proved the union had been telling the truth. It had always maintained union action had nothing to do with Warner's concerns and it had been about employment law, the high Kiwi dollar and subsidies.

A spokesman for Mr Brownlee said the Government was comfortable with its actions.

Jackson's spokesman said late last night that the illegitimacy of the union meant the blacklist would inevitably be lifted but the union had dragged out the issue in a bid to "save face". The law clarification gave the studio confidence it could film here, he said. NZPA