Here is the sequence of events in the row over the 1,023 foreign prisoners who were released without being considered for deportation:
The first of the 1,023 foreign nationals at the centre of the row is freed after serving their sentence.
However, the offender does not face a hearing for deportation, as required of the Immigration and Nationality Directorate.
Over the next seven years, more than 1,000 more also escape scrutiny on release from jail.
HM Inspector of Prisons' annual report talks of an "institutional blind spot" for foreign nationals within the prison service and a dilatory attitude from the Immigration Service, "which unless pressed, was not monitoring those liable to deportation and making arrangements for this to take place as soon as sentence had expired".
Another HMPI report reveals that a new prison service order "provides no guidance to prisons on work with foreign nationals beyond their status as potential immigration detainees".
Home Office officials first become aware that a number of foreign criminals have been released from UK jails without being considered for deportation, according to a subsequent briefing by the prime minister's official spokesman.
In some instances, action on criminal cases was not being initiated until a late stage, allowing insufficient time to make preparations for removal before the end of sentence
National Audit Report, July 2005
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The National Audit Office, an independent watchdog, publishes a report on returning failed asylum applicants, which warned that preparations to remove foreign criminals from the UK should begin "much earlier".
It said officials were unable to say how many failed applicants had been released from prison because removal could not be arranged.
Mr Clarke has admitted that his attention was first brought to the problem on publication of this report.
The government proposed extra investment, and according to the prime minister, nearly £3m more has since been invested in increasing resources in the key areas.
The Home Office has since revealed that 288 of the 1,023 were freed after August 2005.
Conservative MP Richard Bacon raises the issue during a meeting of the cross-party Public Accounts Committee in the Commons.
He asked what happened to foreign nationals - particularly asylum seekers - on release from prison.
It was around this time that Mr Clarke says he became "fully aware" of the scale of the issue.
He told BBC's Today programme that he "set in motion a whole set of procedures to change the way the prison service and nationality directorate were working".
The Home Office then told Parliament that a new system was in place to correct the inadequacy.
The Home Secretary warns Prime Minister Tony Blair that hundreds of foreign prisoners have been freed without the required investigation into whether they should be deported.
Mr Clarke has since told the BBC: "He agreed we needed to take very strong steps to deal with it."
Ministers become aware that 288 more foreign prisoners had been released since August 2005, despite the changes they had pledged to implement.
A third successive annual report by the prisons inspectorate highlights shortcomings in foreign nationals policy.
The Public Accounts Committee (PAC) publishes its report on returning failed asylum applicants, criticising the inefficient way they were handled.
The report, based on investigations by the cross-party committee of MPs, notes that between 2001 and August 2005, "403 foreign nationals were released from prison without deportation proceedings being completed".
One member, Conservative Richard Bacon, writes back to the Home Office requesting more information.
Sir David Normington, permanent secretary at the Home Office, realises the figures were wrong and alerts the home secretary.
25 APRIL 2006
FREED SINCE AUGUST 2005
September - 61
October - 49
November - 34
December - 49
January - 40
February - 30
March - 25
Source: Public Accounts Committee
Knowing the issue would emerge at the PAC hearing on 26 April, the Home Office admits more than 1,000 foreign criminals were released between 1999 and March 2006 without being considered for deportation.
Mr Blair is told that murderers and rapists have been released just four days before the public, and more than three weeks after Mr Clarke was made aware.
Mr Clarke says he offered to resign, admitting it was his responsibility, but the prime minister tells him he does not consider it necessary.
28 APRIL 2006
The home secretary reveals that five of the criminals convicted of serious offences have committed new crimes since their release, including violence and drugs offences. One of them is also facing rape allegations. Mr Clarke insists he will stay in his job to repair the situation.
1 MAY 2006
It emerges that it took Mr Clarke three weeks to tell the prime minister that serious criminals were among the prisoners not considered for deportation. The Home Office says it briefed Mr Blair when it could give him full details.
3 MAY 2006
Mr Clarke promises new laws to make it a presumption that any foreigners convicted of an imprisonable offence should be deported automatically unless there are special circumstances.
He says deportation action is being started against 70 of the most serious offenders but the Home Office has only accounted for 32 of them. The Tories say the government has lost control.
5 MAY 2006
Charles Clarke is sacked as home secretary and refuses the offer of another Cabinet post. Defence Secretary John Reid is named as his successor.
8 MAY 2006
The new home secretary revises the number of serious offenders freed without being deported from 90 to at least 150. And he says the final figure could end up being "several hundred" if armed robbers are included in the category.
15 MAY 2006
John Reid reveals that one murderer is among the freed criminals still at large. He again changes the figure for the number of serious offenders on the list and says there are 179, with 81 of them in the government's control.
The home secretary says 880 of the total 1,023 cases have been considered for deportation. There has been an initial decision to deport in 649 cases.
16 MAY 2006
Cabinet Secretary Gus O'Donnell says civil servants should not resign over the foreign prisoners fiasco which cost Charles Clarke his job.
17 MAY 2006
Conservative leader David Cameron accuses Tony Blair of making up policy as he goes along over deportation of foreign prisoners.
The prime minister insists he has not shifted his position - he wants the "vast bulk" of foreign prisoners to be deported automatically "irrespective of any claim that they have that the country to which they are going back may not be safe".
20 MAY 2006
Attorney General Lord Goldsmith says the UK is to ask the European Court of Human Rights to review its absolute ban on deporting people to countries where they could face torture or death.
22 MAY 2006
Tony McNulty, one of the ministers under fire in the foreign prisoners debacle, is replaced as immigration minister by Police Minister Liam Byrne in a Home Office reshuffle.
A Home Office spokesman rejects claims the move was a result of recent immigration scandals.
23 MAY 2006
Home Secretary John Reid says 85 of the 186 serious foreign released prisoners are still at large.
Of the 37 "most serious" offenders, 27 are in jail, including four murderers, and two are thought to be dead, he tells MPs.
24 MAY 2006
Mr Reid apologises after figures he gave MPs the previous day on
the foreign prisoners releases proved to be wrong.
Of the serious offenders he said were in prison, some had in fact been
released on bail.
25 MAY 2006
Home Office Permanent Secretary, Sir David Normington, tells senior police officers he deeply regrets the sacking of ousted Home Secretary Charles Clarke.
He says the series of crises at the Home Office has caused "immense
damage" to the department.
26 MAY 2006
Foreign inmates at Ford open prison in Sussex are returned to closed prisons after 11 absconded in May.
The escapees had convictions for offences including drugs offences and fraud.
27 MAY 2006
The Home Office is looking into reports hundreds of foreign offenders have been freed from secure hospitals without being considered for deportation.
A newspaper report says police are seeking up to 500 former mental patients, including murderers, rapists and paedophiles.
24 SEPTEMBER 2006
A unit set up to trace dangerous foreign criminals is closed by the Home Office.
Police officers recommended that the unit be closed down rather than it being a political decision, Mr Reid said. Other efforts to ascertain the fate of the remaining criminals continue.
9 OCTOBER 2006
Three of the most serious offenders at the centre of the foreign prisoners row which erupted in April remain at large six months on, the Home Office says.