Fathers 4 Justice have made headlines by flour-bombing the PM, climbing the walls of Buckingham Palace and invading York Minster. But who are they? With a Channel 4 documentary due to be screened on Monday, STEPHEN LEWIS tries to find out.

THERE are times when all very young children need a bit of comfort. When they fall over and bump themselves, say. Or when they wake up from a bad dream.

At such times, there is only one thing that Martin Cottrell's four-year-old son Leon wants.

"He will say 'I just want mummy and daddy together'," says Martin. "That tears at you."

It tears at him because, no matter how much Leon may long for it, Martin knows it is never going to happen.

Like so many marriages - as many as four in ten, according to some figures - Martin's ended in divorce. It was a bitter, acrimonious divorce that involved lawyers and an emotional tug-of-war over access to Leon.

The emotional scars run deep. Martin's own anger is such that when he talks about his ex-wife, he refers to her coldly as 'the mother'.

None of that, however, has stopped Martin being Leon's dad. His own parents separated before he was born, he says. "And to me, personally, being a good father is one of the most important things in my life."

Which is why, when he found his role in Leon's life being marginalised after the divorce, he became desperate.

Leon now lives with his mum in West Yorkshire. Martin, who moved to York from Ireland to be nearer to him, gets to see him every weekend - a full two days one week, a single day the next. But still he is left feeling more like a visitor than a dad, he says.

"I want to be involved in all aspects of his life, such as school, his health, teaching him right from wrong," he says. "I want to help him with his homework, play football with him after school, do special things with him. But I feel I'm not allowed to be the father that my son deserves."

What makes him really angry is the way he says the system is biased against him because he is a man. It was his ex-wife who wanted to end the marriage, he says. It was his ex-wife who, following the split, "blew up" every time he tried to discuss the situation. It was his ex-wife who constantly threatened to stop him seeing his son, so that he had to go to court to get a contact order.

And it is his ex-wife with whom their son now lives.

"It does not matter how good a dad you are," he says bitterly. "The family courts make a presumption against the father. Lawyers will say that mothers provide the care for children, and that the child needs to reside in the matrimonial home. But that's not true!"

It is this sense of anger and injustice that drove an ordinary man to become an activist. Martin is now the Yorkshire co-ordinator of Fathers 4 Justice, the campaigning group which over the last year has hijacked the headlines thanks to a series of increasingly audacious stunts.

In May, they chucked a flour bomb at Tony Blair during Prime Minister's Questions, prompting an embarrassing debate about security in the Commons.

In July, a group of protesters dressed as priests stormed a Church of England synod meeting at York Minster, before holding a roof-top sit-in.

And on September 13, a Fathers 4 Justice campaigner dressed as batman evaded the royal police force, shinned up a ladder and edged his way on to Buckingham Palace's famous balcony. To the embarrassment of the security services, he stayed there all day and the images were beamed around the world.

Martin won't say whether he was directly involved in any of these but he will be taking action in future, he says.

Fathers 4 Justice has proved devastatingly effective at generating publicity, so much so that on Monday Channel 4 will be devoting a one-hour documentary to them.

But do they have a case?

There is no doubting the strength of their feelings of grievance. Gloucestershire painter and decorator Jason Hatch - aka the Buckingham Palace Batman - describes being unable to see his children regularly as a form of "living bereavement". It's a vivid phrase which captures well the desperate anguish of fathers who feel they are denied the right to play a part in their children's lives.

All Fathers 4 Justice want, Martin insists, is for fathers to be treated the same as mothers after divorce or separation. They want an end to the automatic presumption that children should live with the mother, compulsory mandatory mediation following separation, and tougher action against mothers who arbitrarily deny fathers contact with their children, often in the teeth of court orders.

"Both parents should be treated as equals," he says. "The starting point should be that the child should be allowed to spend equal time with both parents. From that position both parents should then be able to sit down, with the unbiased support of professionally trained mediators, and work out what is the ideal solution for the child in their particular circumstances."

Marilyn Stowe, a top family lawyer from Harrogate who is chief assessor of the Law Society's family law panel, concedes that Fathers 4 Justice do have a point.

She doesn't condone their methods - some of their activities, she says, are very extreme. "But I genuinely do think there is a problem with the law. I have heard from a lot of fathers not involved with Fathers 4 Justice - civil servants, teachers, ordinary dads - who have had it tough."

In theory, both parents have equal responsibility and obligations to their children after divorce or separation under the law, she says. But in fact, the parent with whom the child lives - and that is usually the mother - holds all the cards.

In most cases, the parents are able to amicably agree contact arrangements, she says. But in some cases the parent with whom the child does not live (usually the father) has to fight for contact. That's when emotions can get out of hand, and the child can be caught up in a tug-of-love over access.

So Marilyn, head of family law at Harrogate solicitors Grahame Stowe Bateson, agrees that there needs to be change. She would like to see both parents being given equal time with the children as a starting point following divorce or separation - with the children moving between two homes, for example - and a parent who wanted to have them more of the time being required to argue the case for it.

The most important thing, however, must always be the interests of the child, she says. In the welter of emotion and anger that follows a painful separation or divorce, it is easy for the child's needs to get sidelined.

"Everybody thinks they are acting in the best interests of the child," she says. "But are they?"

Martin believes that the activists of Fathers 4 Justice are.

"We believe that the best for children is for them to have both parents," he says. He dismisses the suggestion that members of Fathers 4 Justice are extremists. Nobody was hurt at Buckingham Palace or York Minster, he points out - and the bomb thrown at Tony Blair contained flour.

"Fathers 4 Justice is a peaceful, non-violent direct action group campaigning for the rights of children," he says. "We're just ordinary dads, desperate dads.

"Fathers have been campaigning for their children's rights for 30 years. They have talked to governments, ministers, clergy, sent petitions to the Queen, set up self-help groups. But they have been ignored. Now it is time for dads to stand up against injustice."

BATMAN: The Man Behind The Mask

The man who climbed on to Buckingham Palace's balcony wearing a Batman costume was 32-year-old Cheltenham painter and decorator Jason Hatch.

Speaking to the Evening Press, he claimed that, despite court orders granting him contact, he had been denied access to his three children for three years and three months. It was, he said, a "living bereavement".

He lived just 75 feet away from the home where his children lived with their mother, he said, and could watch the children walking to school every day, but did not dare approach them for fear of being served with a 'molestation order'.

"I just feel desperate," he said. "At least when they see me on TV, they know that's their dad, and that I'm not giving up fighting."

Dad's Army: The Men Who Stormed The Palace is on Channel 4 on Monday, October 11, 2004 at 9pm.

Updated: 11:23 Friday, October 08, 2004