Ms Kelly has promised further discussions with Labour MPs

Sceptical MPs questioned her about the planned "trust schools", which would have greater freedoms to innovate.

The challenges followed Tuesday's White Paper which is said to have caused rows within the Cabinet too.

Ms Kelly promised trust schools would follow a national admissions code, with safeguards for vulnerable children.

'Damaging'

David Clelland told her many of his fellow Labour MPs "cannot possibly support these proposals in their current form".

They would be potentially damaging, he said, to many young people.

He hoped she would have "meaningful discussions" with Labour backbenchers before proceeding.

Ms Kelly said the proposals were about "driving up standards across the board" but particularly meeting the needs of the most disadvantaged youngsters in the most disadvantaged areas.

Schools would have the opportunity for "real professional help", could federate with other schools and have "a sense of purpose and mission".

'Cherry picking'

Another Labour MP, Jeff Ennis, asked how trust schools would be required to take "their fair share" of children with special educational needs and those entitled to free school meals, "rather than just cherry picking the best students".

Ms Kelly stressed that the new schools would have to conform to the national code of practice on admissions.

She would shortly publish regulations giving priority to children in council care and giving children with statements of special need an automatic right to a place in any school named for them.

By 2007 she expected all schools would be taking "hard to place" children.

But she was forced to concede to Liberal Democrat spokesman Ed Davey that the admission code is not legally binding.

Last week she was unable to overrule the London Oratory school - attended by children of the prime minister - which is continuing to interview prospective parents.

Protection

Helen Jones, Labour MP for Warrington North, asked what consultations a school would have to have with its neighbours if it planned to become a trust.

"Many of us have concerns about the White Paper because it talks about schools as if they exist in isolation," she said.

"What procedures do you intend to put in place to protect those children in schools whose numbers may be falling?"

Ms Kelly said part of the new plans was the "freedom to collaborate with other schools". Local authorities would have a strategic overview.

But Leicestershire MP David Taylor said the plans would "enfeeble and marginalise" local authorities.

Freedoms

Conservative education spokesman David Cameron challenged Ms Kelly to say what automatic freedoms a trust school would have that were not enjoyed already by the existing foundation schools.

She told him the aim was to make those freedoms "much more easily available", in negotiation with her department.

Mr Cameron said the real answer was they would have no automatic rights.

But when he asked how many trust schools she thought there would be by 2007, Ms Kelly said many - "perhaps, over time, the majority".

Her department said afterwards that it had not had any expressions of interest from schools as yet.

A spokeswoman said trust schools were just a proposal. If it was accepted, it was not envisaged that they would start for at least the next financial year.