Prime Minister Tony Blair spoke publicly yesterday about how his father, Leo, was fostered when his travelling entertainer parents left him with a couple they met on tour.

Mr Blair was speaking as he met a group of adopted children and their families, with his wife Cherie, to coincide with the launch of a White Paper on adoption.

The Prime Minister has taken a personal interest in the adoption reforms, chairing a Cabinet committee on the issue.

He and wife yesterday met a few of the 300 adoptive families and children placed through the Coram Family Centre, England's oldest charity, which specialises in placing children who have suffered abuse or neglect, and those who have disabilities or learning difficulties.

Amuda and Ian, who declined to give their surnames to protect their children, told of their struggle to adopt their son Gareth, now nine, six years ago.

"Adoption is a very long road. It's that commitment beyond normal parenting. It will take Gareth a whole lifetime to overcome what he experienced in the first three years of his life," said Amunda.

After listening to the families' problems coping with the bureaucracy of the adoption system during an informal chat at the Coram Family Centre in St Pancras, north London, he said: "My own father was fostered. In those days there weren't any rules at all.

"I don't think my grandmother would have passed any tests at all. But then a framework of rules grew up in a very random and ad hoc way. Now is the right time to get back to basics and ask what we want to achieve for children."

He added: "I know how much difference a loving and caring family made to me. My own father was adopted and not brought up by his own parents."

Mr Blair's father Leo was the illegitimate son of travelling entertainers Celia Ridgeway and Charles Parsons.

The social stigma of having a child out of wedlock and their hectic lifestyles prompted Leo's parents to give him to poor Clydesdale ship worker James Blair and his wife Mary, who they met on tour in Glasgow.

Leo Blair went on to become a successful barrister, although his foster mother Mary prevented contact between him and his biological family.

Leo was later reunited with his biological half-sister Pauline Harding. The Prime Minister, his wife and their three eldest children were present at the emotional family reunion.