Revealing that 85 serious foreign offenders who were not considered for deportation are still at large, John Reid has told MPs the Home Office's immigration division is "not fit for purpose".

The home secretary was on Tuesday seeking to defend his department's performance over the foreign prisoners row and a string of other failures.

Giving evidence to the Commons home affairs select committee, Reid detailed the latest progress in dealing with the 1,019 foreign prisoners who should have been considered for deportation but were not.

He also revealed that all the cases had now been assessed and that consideration for deportation had begun in 999 cases.

There had been initial decisions to deport in 778 cases. Of those, 197 people are currently in custody, one is electronically tagged, 10 are reporting regularly to the immigration service or Prison Service, and 37 have been deported or removed.

The number of the 'most serious' offenders - including murderers and rapists - had also risen by two to 37, of which 27 were now in prison - including all four murderers - and two were thought to be dead, leaving eight at large.

Problems

Reid also sought to put the variety of immigration-related problems facing the ministry in the context of the "huge torrent of problems" created by the end of the cold war, including mass migration, civil wars and failed states.

"There have been some successes in response to that," he added, pointing to the increased removal rate of failed of asylum applicants and reduced number of asylum claims.

But he said the immigration system the government inherited had been "inadequate in terms of its information technology... leadership [and] management".

And he pledged a "fundamental overhaul of the Immigration and Nationality Directorate", publishing eight action points for improvement.

While he agreed that there had been failures of accountability among civil servants - saying MPs should not "count on" no staff being sacked - he said he was not sure the department was "culturally" dysfunctional.

Reid also said he did not accept the argument that the ministry should be broken up, arguing that its core functions of policing, immigration and intelligence needed to work together in the fight against terrorism and crime.

"I don't myself see the argument for splitting up the Home Office as an a priori priority," he said.

Reshuffle

Following his own reshuffle earlier this month, Reid also defended the decision to switch former immigration minister Tony McNulty to the policing portfolio on Monday.

Fast-rising minister Liam Byrne will now be responsible for immigration, asylum and citizenship.

Reid said he had put Byrne in charge "because of the qualities from previous experience he can bring".

However he denied that McNulty had been demoted, saying the police portfolio was a serious and important role.

And Number 10 confirmed that the home secretary had discussed the job switch with Tony Blair.

"John Reid did discuss the move with the prime minister. The point is you play to people's strengths," said the prime minister's official spokesman.

"Liam Byrne has a background as a consultant and he is used to managing projects and change-management and this is certainly a change management project."