Key Points:

Leading National Party figures received correspondence in May 2005 telling them the Exclusive Brethren were planning a major election pamphlet campaign, investigative author Nicky Hager's new book says.

It is one of several claims in The Hollow Men, released today after an injunction covering outgoing National leader Don Brash's stolen emails was lifted.

The book, subtitled A Study in the Politics of Deception, contains several of those emails.

Mr Hager today said a key claim he could now reveal was that on May 24 the Brethren put their plans for a $1 million campaign in writing to Dr Brash and National's finance spokesman John Key.

"They said it was solely for the purpose of getting party votes for National, but they also said there were two parts to this 'building mistrust in the Government' and 'building trust in a Brash-led government'," Mr Hager told reporters.

Dr Brash has said the first he knew of a Brethren pamphlet campaign was in August last year.

Mr Hager said Dr Brash himself forwarded the email to then campaign manager Stephen Joyce.

In his opening chapter The Path of Principle, Hager writes that National and the Exclusive Brethren's first interaction was on April 5, 2005, at a National Campaign Strategy Meeting.

"One of the items on the agenda that Tuesday was the bland-sounding 'Outside Groups - Defence and Education'... Unbeknown to the rest of New Zealand, a large anonymously funded advertising campaign was scheduled to begin at the end of that week - early April 2005 - stridently attacking Labour's defence and anti-nuclear policies..."

The campaign, which consisted of newspaper advertisements and about a million pamphlets distributed throughout the country, was funded by the Exclusive Brethren and cost $350,000.

According to Hager, chief of staff Richard Long emailed Brash on the morning of the strategy meeting, saying: "It might pay to know that the Brethren advertising campaign to repair defence links (bring back the ships) will start this Friday."

After Dr Brash dropped his support for the Civil Union Bill, Hager alleges contact between National and the Exclusive Brethren became increasingly frequent and that on February 14, 2005, Brash met with Doug Watt and other Brethren Church members in his parliamentary office.

From this time onwards, Hager writes that "Exclusive Brethren representatives and Brash would snatch opportunities for meetings as he was travelling and electioneering."

Though Hager notes some National Party MPs had "misgivings about the Exclusive Brethren support," they were largely ignored.

Throughout May 2005, Hager says that National and the Exclusive Brethren held a series of discussions over the planned election advertising. On May 24, Ron Hickmott of the Exclusive Brethren wrote to Brash and finance spokesman John Key, reminding them they were the backers of the "Wake Up NZ" campaign and that it was important that they met to discuss "a very extensive election campaign ($1,000,000) with the sole goal of "Getting Party Votes for National".

"Our campaign (a total of seven nationally distributed flyers) is direct and simple: - It creates and demonstrates MISTRUST in the current Government. It builds TRUST in a DON BRASH led National Government."

The letter arrived nearly four months before the election and Hager alleges that the Exclusive Brethren continued to discuss their plans with National throughout June.

In June 2005, National's Napier electorate campaign manager Simon Lusk emailed Brash's assistant Bryan Sinclair, writing: "Some of the ads we were discussing in Napier were shown to a selection of MPs yesterday."

Hager says these documents confirm that "months before the election campaign, National Party MPs and staff - who would later earnestly deny any knowledge - were fully aware of the Exclusive Brethren advertising campaign plans and that at least some MPs had the seen the draft publications."