Charles Clarke - who was sacked as home secretary over the foreign prisoners scandal - has launched a fight back setting out his side of events.
Mr Clarke was sacked as home secretary in May
Mr Clarke, the high-profile casualty of the May reshuffle, has written to the Commons home affairs select committee as part of its probe into the affair.
He sets out measures he took once he learned foreign prisoners were being freed without deportation considered.
Successor John Reid says parts of the Home Office are not fit for purpose.
In his letter, Mr Clarke says two issues - the number of foreign prisoners and the fact some of them were not considered for deportation - have become confused in the media's coverage of the foreign prisoners affair.
He says: "I was probably responsible, at least in part, for some of this confusion because I was mindful of my duties as home secretary and thought that it was important and proper that I should take overall responsibility.
"However the suggestion that from July 2005 I had personally known about the failure to consider deportation and done nothing about it was wrong.
"As others have already made clear to the committee, it was only in late March 2006 that ministers, including myself, were made aware of the failure to consider for deportation some foreign national prisoners at the end of their sentence, and when we were aware of this action was then taken."
Mr Clarke says the increase in numbers of foreigners in British jails since the late 1990s represented an "obvious pressure point" on the capacity of the prison system.
The issue fell across a "key Home Office fault-line" - the relationship between prisons and the Immigration and Nationality Directorate (IND) - he says.
Mr Clarke says he was aware of the foreign prisoners issue when he became home secretary in December 2004 but it was only one of the many "pressing" concerns within the prisons and probation system.
In September 2005 he realised the scale of the problem and immediately asked officials for an urgent action plan for reducing the foreign prisoner population.
More money was poured in and Mr Clarke sought more effective international agreements and a better relationship between the prisons system and IND.
He told Tony Blair about his concerns about the "broad issue" of foreign prisoners in November 2005, saying he was "urgently" exploring options for reducing the numbers.
Mr Clarke goes on to stress: "I was not at that stage aware of the fact that FNPs (foreign national prisoners) were being released without being properly considered for deportation so I did not discuss this matter with the prime minister."
Mr Clarke points to a legal ruling about the murderer of head teacher Philip Lawrence - Learco Chindamo.
Judges said it would be "premature" to decide just two-and-a-half years into Chindamo's life sentence that he should be deported on his release.
"After this the decision was taken that deportation should not be considered until towards the end of a prison term," Mr Clarke wrote.
The improved communication between IND and prisons also produced more referrals and more foreign inmates were identified thanks to new systems.
"Officials are clear that although the general issue of increased numbers and staff overload was logged with ministers, ministers were not told that some foreign national prisoners were being released without being considered for deportation, nor was the real seriousness of the situation appreciated even by senior officials," Mr Clarke writes.
They were made aware of a problem of "uncertain magnitude" on 17 March 2006, Mr Clarke then received the information on 31 March while Parliament was having its Easter recess.
Setting record straight
Mr Clarke said he had two main concerns: putting the record straight with MPs who were given misleading information; and taking "urgent steps" to pursue those foreign prisoners not previously considered for deportation.
But looking back he is sure it would have been better to start pursing the prisoners earlier, at least after the 31 March warning from officials.
Asked about Mr Clarke's comments, Tony Blair's official spokesman said: "We have been over this in the past. The reasons for [Mr Clarke's] removal were set out at the time. He was offered a post in Cabinet and he chose not to accept it."
Former Home Office Minister Fiona MacTaggart said she thought Mr Clarke had been treated unfairly - though she recognised Mr Blair's right to choose who did what in government.