'You can't play at being a dad for two years and not pay up'

Andy Bathie now has to pay £450 a month toward bringing up the two children produced using his sperm. He insisted he was only a donor and did not want take an active role in raising the youngsters.

But the mother has hit back, claiming the 37-year-old changed his mind and regularly saw his four-year-old daughter.

Terri Arnold, from Clacton, Essex, said Mr Bathie would take the girl to stay with him overnight and even took paternity leave to care for her.

She said: "At first the idea was that he wasn't going to have anything to do with the children. He said he was going to draw up a contract saying he had no responsibility for the children and that he would be Uncle Andy.

"He was Uncle Andy but after the christening he said he didn't want to be the uncle - he wanted to be the daddy. He was seeing her roughly once a month - she would stay over at his house."

The mother of two became pregnant after a DIY artificial insemination. She said Mr Bathie originally wanted nothing to do with his daughter, who is now four, but started seeing her regularly after her christening when she was five months.

Ms Arnold said: "We were going to go to a clinic (to arrange a sperm donor), we approached our GP about it, but then Andy offered. He said it was probably his only chance to be a father. Andy was a friend of my partner and we trusted him.

"We've got photographs of our little girl at his home, we've got a box full of birthday and Christmas cards from him saying 'from daddy'. He bought her a silver trinket box and engraved it 'daddy'. He had been seeing her for two years, she became very attached to him."

Ms Arnold said Mr Bathie helped pay for his daughter's pram and shoes and regularly bought her presents.

Two years after her birth Mr Bathie became the couple's sperm donor for a second time and Ms Arnold gave birth to a boy. He suffers from a serious digestive problem, which is being treated at Great Ormond Street Hospital.

Mrs Arnold, 25, said: "When we had the second child, we had a long discussion about it and we agreed he was going to have the same responsibility and he said, 'Fine, I'd love to have another one'. He went into it with his eyes wide open." Mrs Arnold gave birth to the second baby, a boy, at Colchester Hospital in Essex, in October 2005. She claims Mr Bathie asked to be present and even took paternity leave from the fire service to look after the elder child.

Mrs Arnold, who has since split from her partner, said that shortly after the birth of the boy, now two, Mr Bathie stopped seeing his children.

She said the fireman is not named as the children's father on their birth certificates but claims she was forced to give his name to the Child Support Agency when they threatened to cut her income support.

"How can be turn his back on his disabled son?" She added: "He's portrayed me as just being after his money but I'm not. I don't care about his money - I just care about my kids, his kids.

"You can't play at being a dad for two years and then just leave. Our little girl kept asking when she was going to see her daddy again - what can you say to a child?

"The money is not for me, it's for their food, clothes and shoes. This is about a principle and I'll fight all the way. He wanted to be a father but he doesn't want the financial responsibility."

Mr Bathie, from Enfield, has launched a legal challenge, thought to be the first of its kind, so that he is not recognised as a legal parent to the children.

He said he cannot afford to start a family of his own because of the thousands of pounds he has to pay in child maintenance.

"These women wanted to be parents and take on all the responsibilities that brings. I would never have agreed to this unless they had been living as a committed family," he said.