More than 150 paediatricians are calling on the Government to scrap its controversial Health Bill, saying it will have an "extremely damaging effect" on the health of children.

In a damning letter to The Lancet medical journal, members of the UK's Royal College of Paediatrics and Child Health said there was "no prospect" of improving the Health and Social Care Bill, currently going through Parliament.

And they accused the Government of "misrepresenting" the Bill as being something that was necessary for the NHS. The signatories join several Royal Medical Colleges, including the Royal College of GPs and the Royal College of Radiologists, in calling for the Bill to be scrapped.

The move will put increasing pressure on Health Secretary Andrew Lansley over the reforms, which have come under repeated fire from healthcare professionals. Unions, including the British Medical Association, the Royal College of Nursing and the Royal College of Midwives are among those calling for the Bill to be withdrawn.

The letter said that "if passed, we believe that the Bill will have an extremely damaging effect on the health care of children and their families and their access to high-quality, effective services".

It added: "We see no prospect for improvement to the Bill sufficient to safeguard the rights of access to health care by children and their families. In our view, no adequate justification for the Bill has been made.

"The costs of dismantling existing National Health Service structures are enormous and, at a time of financial austerity for all public services, have resulted in precious resources being diverted to private management firms and away from frontline patient care. We believe that the Bill will undermine choice, quality, safety, equity, and integration of care for children and their families."

The signatories said the NHS already "outperforms most other health systems internationally and is highly efficient" and expressed fears over the potential role of private companies in managing groups of GPs, who will control most of the NHS budget, under the new system.

A spokeswoman for the Department of Health said: "We have listened and substantially strengthened the Bill following the listening exercise. It's not true to say that the Health and Social Care Bill will fragment children's healthcare.

"In fact, the Bill will help address the very concerns about fragmentation that the experts raise. It will help the NHS and other public services work together better for children, young people and their families."