Last Wednesday, Mark and Nicky Webster were told they will never see three of their children again, even though a judge accepted that allegations of abuse could be false. Their story was the lead item on the following day's BBC news, and appeared in several newspapers with pictures of the couple and quotes of them saying they felt they had been the victims of a miscarriage of justice.

But as of April, because of a change in legislation being introduced by Jack Straw, the Justice Secretary, the media will no longer be able to identify those involved in cases such as the Websters. It will also be illegal for any children currently in care to speak out, even if they feel they are being maltreated.

The change, unremarked by the press, comes within an overhaul of the law on the reporting of family courts that has otherwise been widely welcomed by the media. Currently there is a blanket ban on journalists entering family courts, but in December Straw announced a change to the law that will allow journalists to attend family court hearings. "A really important veil is being lifted on what happens in these courts" he said. The change was greeted warmly, particularly by The Times, whose columnist Camilla Cavendish had led the campaign to open up the family courts, for which she won the Paul Foot Award. But what The Times omitted to mention was a line, slipped in at the end of Straw's statement, stating his intention to reverse the decision in a case known as Clayton v Clayton.

Download the new Independent Premium app Sharing the full story, not just the headlines

Simon Clayton is an intense 47-year-old book-seller from Hay-on-Wye. In 2003, he astonished locals in the Welsh border town by abducting his seven-year-old daughter, days ahead of a divorce hearing, fearing he would lose custody to his wife. He was tracked down to Portugal and brought home under arrest, after which he fought a lengthy custody battle.

When his case was concluded, Clayton found he was legally barred from offering a public explanation for what he had done. He fought the existing legislation, and in 2006 the Court of Appeal reached a landmark ruling that a parent should be allowed to identify himself and his child and tell his story. It was decided that a parent's right to freedom of expression was greater than a child's right to privacy.

It is because of that Clayton v Clayton ruling that the Websters were able to speak of their distress on Thursday. "Reversing it will mean that any child or adult who has been in a family court case cannot identify themselves in public," says Clayton. "The implication of this for papers is bad – editors are only interested in a story if it has a human dimension, if you can see the people or read about them by name."

Liberal Democrat MP John Hemming agrees: "There are two issues here. One is that the press will be prevented from reporting cases like the Websters with their names and faces. The other is that, at the moment, children who are in care are entitled to speak out if they are unhappy, although it doesn't happen very often because nobody knows how to do it. The effect of this change will be to gag them."

Since Clayton v Clayton there have been no complaints of invasion of privacy. "Fran Lyon, Angela Canning, Bob Geldof, Jack Frost – there are more than a dozen people who have benefited from being able to go public with their stories," says Clayton. "There are thousands of people like the Websters out there who, once their cases are over, will want to log on to a forum and discuss what happened to them and get support. As of April, it will be illegal to identify yourself in any way that could lead to the identification of the child." Similarly, there are occasions when the children may wish to make a public statement.

Clayton is incensed that Straw is claiming to be opening up the family courts while reversing the Court of Appeal's ruling, and says he has yet to receive an explanation, or any reply, from Straw's office. A Ministry of Justice spokesman said: "The Secretary of State has made it clear that any move towards openness in the family courts must be balanced with the welfare, privacy and well-being of children." She added that the decision to reverse Clayton had been made following a consultation with a variety of bodies. For better or worse, the balance has been tipped against openness.

Some say the child must come first, end of discussion. Others see a sinister attempt to gag those who say the system doesn't work. Cavendish takes a less conspiratorial view, but is nonetheless perplexed about the reversal of Clayton. "It won't cancel out the new legislation but it will make it increasingly difficult to report these cases," she said. "I'm afraid I don't know why it is happening."