Men's rights campaigners claim they've been silenced by a government select committee reviewing controversial planned changes to the Family Court.

Wellington psychologist Craig Jackson said he was told to cut part of his submission or he wouldn't be heard; another campaigner, Adam Cowie, appears to have been excluded entirely.

Jackson and Cowie are among 350 submitters on the bill, but Justice and Electoral Reform committee chairman Scott Simpson says he hasn't gagged anyone, but has to tread a careful line when discussing custody battles.

Lawyer and former MP Stephen Franks said parliamentary committees usually "lean over backwards, even to hear nutters" but the justice committee had a "real tension" between hearing the information they needed and not allowing people to air vendettas or say something defamatory. "[But] in this case, quite frankly, they ought to want to know the horror stories if they are looking at a reform of a court procedure."

Cowie, who wrote a fictionalised account about his bitter custody dispute with his former wife, says he received no reply to his submission, despite indicating he wanted to make a personal appearance.

Jackson, whose submission quoted Cowie's self-published Separated with Children, said he was told to excise any reference to Cowie or his submission would be refused.

"Adam's case showed a complete failure of the system, that's why they have tried to draw a curtain of silence around it because it is a damning indictment of the family courts," Jackson said. "His case was a wonderful illustration of the complete failure of the system to do anything effective to protect children's welfare, if nothing else."

Jackson said he planned to use excerpts from Cowie's book to illustrate his argument that reforms should recognise parental alienation of children as a psychological abuse sometimes perpetrated by women against men. But he says he was told to cut all reference to Cowie and that the committee wasn't prepared to hear Cowie's own submission: "It was an ultimatum."

Jackson did produce a redacted version and says he was heard politely during a 10-minute appearance on Thursday.

The proposed changes to the Family Court have attracted an outcry from specialist lawyers and men's and women's groups alike.

Simpson, National MP for the Coromandel, said his committee had a duty to uphold natural justice and protect identities of children and former partners in individual cases.

Some submissions, he said, "were quite raw in their content, where people want to tell their personal story or history in court . . . we have to consider natural justice and protect the rights of those that are not present, because there are always two sides to every story".

- Sunday Star Times