Prime Minister Helen Clark calls them weird. Labour's energy minister David Parker has dubbed them the Christian version of the Taliban.
The Exclusive Brethren's interpretation of the Bible has certainly resulted in more restrictions and prohibitions than the usual fundamentalist Christian sect.
In a bid to "practise separation from evil" the brethren do not go to university, do not eat with outsiders and also banned are mobile phones, television, radio, internet, and films.
"Their homes and vehicles are free of the pipelines of media filth," the Exclusive Brethren's website (www. theexclusivebrethren.com) says. The irony of having a website when internet usage is forbidden appears to have been lost on the sect.
Women, who are not allowed to work outside their family businesses once married, must wear headscarves and must not cut their hair. No artificial birth control is allowed. Men must not wear shorts or ties. The group also eschews restaurants or "venues of worldly entertainment". Members must marry within the fellowship although those that marry outside the brethren can be "recovered" as long as their spouses convert.
They not allowed to bear arms, vote, or join other organisations.
Rules, rules and more rules.
Yet Exclusive Brethren have no monopoly over strict and seemingly odd beliefs. Most religions have practices which appear bizarre to outsiders and even disillusioned former brethren speak of the sect as comprising solid family people who run honest and efficient businesses and care for each other.
Ngaire Thomas was born into an Exclusive Brethren family in Auckland in 1943, and did not leave with her husband and family until 1974. Her book, Behind Closed Doors, chronicles a life in the group spent fighting and beating what she describes as often silly, petty strictures imposed by "sanctimonious hypocrites".
Now living on the Queensland's Gold Coast, Thomas says she was probably too kind to the Brethren in her book, and is writing another. She remains in contact with people who have recently left, or who have been expelled, from the sect.
"Our biggest concern is what they are doing to families. They are trying to say they believe in family values but in fact they break down families."
Any breach of the tightly controlled rules can lead to expulsion from sect, she says. Family and friends who remain are forbidden from social contact with the transgressing member.
Ron Fawkes, a former leader of the Exclusive Brethren in Australia, was expelled in the late 1980s because he disagreed with then world leader James Symington.
In April, he told Australian public radio he had not seen his six children, who stayed in the sect with their mother, in 22 years.
On radio he read out the letters from his children saying they could no longer see him because he was evil.
"The punishment doesn't fit the crime," Thomas says. "There are people who have had their whole family split because a member has used a cellphone or used a computer or watched a television programme. The punishment is that they would be put out."
She says it is maddening for former members to find that activities such as the use of computers that could once earn expulsion are now acceptable.
While the ban on computers and faxes appears to have been lifted, their use is still apparently strictly controlled by the church.
Documents leaked to Australian media show computers can be used in brethren-run businesses, as long as they are leased from a company run by senior members of the group.
The equipment is said to be owned by an entity called National Office Assist which runs out of the same business address as the current worldwide leader of the brethren, Bruce D. Hales.
Some former members see the step as the first move to centralised business accounting.
The origins of the Exclusive Brethren goes back to 1827 when Irish Anglican clergyman John Darby left his church in Dublin to join a group who worshipped in their own homes without clergy.
Various splits followed with the Exclusive Brethren (the Open Brethren are less strict, and have more local autonomy) claiming to be the true followers of Darby's prolific teachings. The sect claims to have 40,000 members worldwide and the membership in New Zealand is thought to number between 5000 and 10,000.
Current leader Hales, known as the Elect Vessel, is an office equipment retailer in Sydney, who is credited with encouraging members to support politicians whose platform meets the group's moral imperatives.
The Brethren website says communication with members of Parliament is encouraged to express a moral viewpoint of legislation.
"They (EB) do not vote but hold Government in the highest respect as God's ministers, used by Him to restrain evil and provide conditions for the promotion of glad tidings," it says.
Pamphlets and greeting cards delivered to homes, usually attacking the Greens and stances on same-sex marriage, have featured in campaigns by brethren members in elections in Canada, New Zealand and Tasmania in the last 18 months. The advertising is ostensibly from private citizens who when outed are revealed to be Exclusive Brethren.
In September last year, seven New Zealand Exclusive Brethren businessmen put their hands up to an anonymous-looking anti-Government and anti-Greens (leaflet and newspaper advertisements) campaign costing $500,000.
Invariably, brethren once exposed say they are acting only as concerned citizens and not church members. This is dismissed as ridiculous by former members, who say independent political action by brethren members is unheard of.
Doug Watt, who runs a large outdoor equipment business in central Christchurch, was one the seven businessmen who came forward last September to acknowledge involvement in the anti-Government campaign.
Watt says the pamphlet campaign was not authorised, directed or funded by the Exclusive Brethren church.
No political party received money from the group of seven "concerned individuals", he says.
Recent snide and belittling attacks on the brethren are designed to promote public ridicule of the church, he says. No group of New Zealanders could tolerate the recent vilification the brethren have been subjected to, he says.
The advertising campaign before the election was not anonymous, he says. The advertising was from private citizens and all authorisations were bona fide.
"There is not, nor ever has been, a requirement to state one's beliefs as part of an authorisation."
In response to claims the Brethren church splits families, he points to a Monash University study which this year concluded the Australian Brethren group lost only a small number of members.
The study found the group had an outstandingly low rate of divorced and separated persons, and it tended to retain its children in active participation, Watt says.
It described the Brethren as a "highly integrated and fully functioning religious community".
"Breakdown of families. Let's look at the facts," he says. "The statistics show marriage breakdown in the Brethren is only 10 per cent of the rate in the wider community."
About 43% of married brethren women are directors or partners performing management tasks in their businesses, he says.
"We have no rule book, but follow the teachings of the Holy Scriptures.
"Our actions are spontaneous responses to the truth of scripture, and of an enlightened conscience," he says.
Senior members of the church did not intend to lease computers to brethren businesses.
"We are happy to use technology where it is appropriate," he says.
He says the latest revelations about National Leader Don Brash's infidelity are beside the point. "We didn't support Dr Brash. We supported a party which appeared to stand for right principles.
"If the Labour Party stood for what is right, we would have supported them."
While it was true brethren were not allowed to bear arms, people should not overlook the fact hundreds of brethren men have been actively involved in the frontline duty in the great wars of the last century. "This service has been in ambulance, medical and driving roles.
"Our stand from scripture is that we do not take life, so we have served in frontline, but non-combatant duty."
"We stand by the truth as it is in Jesus. We have nothing to be ashamed of. We seek to stand by the Cross of Jesus and the truth as set out in the Holy Scriptures," he says.