Beverley Hughes has been given Mr Blair's backing

In a bid to clear a backlog of 29,000 applications, officials were allowed to relax passport checks.

Applicants only had to submit photocopies of their passports and not the original documents.

A Number 10 spokesman said Tony Blair still had confidence in Ms Hughes and other important checks had remained.

'Not about asylum'

"It is important to be clear about what this is," the prime minister's official spokesman said.

"This isn't about asylum, this is not about immigration per se. It is about citizenship applications for people already living in the UK without immigration restrictions."

He pointed out that the Home Office had made clear that people had not been "nodded through" without checks being made.

"One element of case consideration was suspended," the spokesman said.

"But the important checks in respect of police criminal record checks and immigration checks and, where necessary, further security checks were all carried out. In respect of residency checks, there has been an element of discretion there for some time."

Local order?

Ms Hughes has been under pressure in recent days after it emerged immigration officials were told to waive key checks on immigrants from eastern Europe because a backlog had built up.

She has said the order was issued at a regional office without ministers or managers knowing.

The minister said a team in Sheffield processing a particular group of applications had changed some aspects of the procedure without asking the permission of senior managers who advised her.

"Therefore, I could not possibly have known about it," she said.

"As a politician, you are not there to manage staff - this is an organisation of 12,000 people."