Former Speaker of Parliament Sir Peter Tapsell says the controversial "Moonie" peace movement of which he is New Zealand patron cannot be blamed for the breakup of unstable marriages.

"Lots of marriages fail. Maybe they are using the UPF [Universal Peace Federation] as an excuse for partners wanting to escape," he said of criticism of the organisation of Korean evangelist Sun Myung Moon, who was jailed in the United States in the 1980s for tax fraud.

Speaking before a rally of several hundred people addressed in Auckland last night by Dr Hak Ja Han Moon, Mr Moon's wife, Sir Peter said the promotion of traditional families was a crucial part of the movement's prescription for world peace.

He said New Zealand had yet to witness the full long-term effects on its children of the breakup of more than half its families.

Other key ingredients were religious and cross-cultural tolerance, which the movement believed would be boosted if world leaders could be persuaded to build a $315 billion "peace tunnel" across the Bering Strait between Russia and Alaska.

Critics of the organisation, which evolved from Mr Moon's former Unification Church, claim it encourages members to break up with spouses who refuse to join as well.

Sir Peter said he had never heard of any such thing, and was impressed by the movement's promotion of "a very Maori" concept of the ideal family as comprising a father, a mother, children and grandchildren.

The Unification Church was known for its mass weddings, in which thousands of couples were paired up by Mr Moon and his wife from merely looking at photos of followers who had never met one another.

A spokesman for Ethnic Affairs Minister Chris Carter has said the minister had asked for a report into the editorial judgment used by the Office of Ethnic Affairs after questions were raised about its relaying to communities an email inviting people to last night's rally.