This serves no purpose other than to punish one of the most vulnerable groups of children in our society

Asylum Coalition

The home secretary is facing a backbench rebellion over the move, which would see the children educated separately from normal schools.

Mr Blunkett wants to end the UK's so-called "soft touch" on asylum.

But union leader Bill Morris accused the home secretary of playing on people's fear of immigrants and pursuing a policy of "segregation".

'Segregation'

In a strongly-worded attack, the TGWU leader told BBC Radio 4's Today programme: "The government has a policy which argues for social inclusion.

We simply do not accept that the idea that the home office has to run the worst administrative system on earth

Oliver Letwin, shadow home secretary

"But we are debating today a bill which provides for children to be educated separately in these detention centres.

"That is segregation in my book."

The plan has also been condemned by the Asylum Coalition, which includes children's charities, teaching unions, church and refugee groups.

In a letter handed into the Home Office by children from a North London school, the Coalition said: "This will be an assault on the right of all children to equality of access to high quality education."

'Transient population'

But Mr Blunkett said the current policy of dispersing asylum seekers around the country was not working.

What I am not prepared to do is have people come here in very large numbers...and actually claim that they are refugees when they are economic migrants

David Blunkett

Detention centres were necessary to speed up the asylum process and make it fairer for all concerned, he argued.

"We are talking about people who are transient in our country until something like a quarter of them get permission to remain here.

"And that is why accommodation centres, with provision on site, make sense, both for those waiting there and for local communities who then don't have a transient population passing through their services."

'Large numbers'

Mr Blunkett dismissed as "nonsense" claims by Unicef that children in detention centres would receive a sub-standard education.

He added: "What I am not prepared to do is have people come here in very large numbers, larger than anywhere else in Europe, and actually claim that they are refugees when they are economic migrants."

I do not think we should be segregating any children

Neil Gerrard Labour MP

Mr Blunkett's Nationality, Immigration and Asylum Bill is destined for a rocky ride in the Commons, during its report stage debate on Tuesday and Wednesday.

About 30 Labour MPs - including Labour former ministers Frank Dobson, Glenda Jackson and Peter Kilfoyle - are expected to oppose the plan to educate children in detention centres.

Rehabilitation worries

Labour's Neil Gerrard says the idea will hinder efforts to help asylum children integrate in the UK.

"I do not think we should be segregating any children. These are children first and asylum seekers second," he said.

Shadow home secretary Oliver Letwin called on Mr Blunkett to adopt Tory proposals for smaller asylum units that could be better integrated into local communities.

Measures in the bill include:

A pilot phase of asylum seeker accommodation centres Streamlining the appeal process of those denied the right to remain in the UK Raising the maximum jail term for people convicted of harbouring illegal immigrants from six months to 14 years Citizenship ceremonies

But, he added, it was wrong for Mr Blunkett to work on the assumption that the asylum process would take six months or more.

"We simply do not accept that the idea that the home office has to run the worst administrative system on earth.

"What we have to do is run a proper asylum system and process applications quickly."

Under two changes to the bill proposed by the Tories, 10 weeks would be the "absolute upper limit" for asylum seekers to stay in the centres and there would be a limit on the size of the centres.

The home secretary prompted anger earlier this year when he talked of the risk that asylum seekers could "swamp" local schools and doctors' surgeries.