Chief inspector of prisons Nick Hardwick said the report into Wormwood Scrubs prison was "very disappointing".
He said the prison had found it hard to replace experienced staff who left during a major restructuring last year
Although he said there was "some recent evidence" of action being taken to improve performance, there remains "much to be done".
He emphasised the heavy demands being made on staff, saying: "Many staff appeared extremely stretched and some were clearly frustrated that they could not do more; others appeared to have lost focus on prisoners' needs."
One of the country's most well-known prisons has been heavily criticised by inspectors who said it was "filthy", unsafe and under-resourced.
Inspectors said Wormwood Scrubs in west London had "shockingly" failed to put in place recommendations to tackle suicide and self-harm among inmates.
A report from Her Majesty's Inspectorate of Prisons (HMIP) put some of the failings down to a mass exodus of experienced staff after a restructuring last year.
HMIP found many cells meant for one prisoner were holding two, many windows were broken and some of the toilets were filthy.
The report also noted that a "significant" backlog of around 100 new prisoners meant the prison was not coping with the volumes of inmates arriving.
The European Court of Human Rights has ruled that the UK breached prisoners' rights by failing to allow them to vote, but has dismissed claims for compensation by 10 inmates.
The prisoners brought the claim after arguing their rights were violated when they were not allowed to vote in the European elections in 2009.
Speaking for the first time since his release from prison for trying to bring Sharia Law to the streets of London, was Jordan Horner, who has taken the Islamic name Jamaal Uddin.
In December 2012, Horner was filmed at a protest alongside Michael Adebowale who, five months later, murdered soldier Lee Rigby in Woolwich.
He claimed he had converted other prisoners during his time in prison.
Mr Horner said to BBC Panorama:
The prison officers witnessed people become Muslim. In front of them I was giving them what we call Shahada, an invitation and acceptance of Islam.
They were becoming Muslim in front of the prison officers and they felt sort of powerless.
They said I was trying to divide Muslims from non-Muslims, trying to get them to follow an extreme version of Islam.
He added that in less than a year he was transferred between three different jails in an effort to disrupt his activities.
Speaking to BBC Panorama Justice minister Jeremy Wright discussed the threat of Islamic radicalisation behind bars in Britain by saying they should be prevented from inflicting their extreme views on others:
The police and security services do a difficult but important job making sure some of the most dangerous terrorists in this country end up where they belong - behind bars.
Once there, we must make sure they cannot inflict their extreme views on others.
The challenge that our prison staff face should not be underestimated but the public can be reassured - we are committed to tackling extremism."
There is a "significant risk" of Islamic radicalisation behind bars the head of the prison and probation service has told BBC Panorama.
Michael Spurr the chief executive of the National Offender Management Service of England and Wales (NOMS) told the programme:
"There is a significant risk, given the fact that we manage some very dangerous people.
"Our job is to minimise that risk becoming a reality - that somebody in prison becomes radicalised and commits a terrorist offence."
Over the last ten years the number of Muslims in prisons in England and Wales has doubled, with the figure reaching 11,729 in 2013.
There are about 100 al-Qaida-inspired Islamist terrorists behind bars.
Conservatives and Liberal Democrats are at loggerheads over proposals to tighten up the law on knife crime.
Justice Secretary Chris Grayling wants to bring in an automatic six-month jail term for anyone convicted of a second crime involving a knife.
But the chief secretary to the Treasury, Danny Alexander, is concerned that the move would be expensive and put too much pressure on prison places.
A leaked letter from Mr Alexander to Nick Clegg, published in the Daily Mail, says:
‘It is very hard to see how it could be afforded. The Treasury does not support this amendment and I am not willing to clear it."
After a triple murderer was awarded over £800 for lost and damaged possessions, we list 10 very odd compensation claims.Read the full story ›
The triple murderer awarded £815 because his nose hair clippers were broken by a prison guard "should not be paid anything", a Conservative MP told Good Morning Britain.
Nadine Dorries dubbed Kevan Thakrar's claim "quite bizarre" and "difficult to either believe or understand".
"If you or I lose our personal possession we don't have a claim for £800 to repay us. And most of this payment was made because a prison officer failed to apologise because he was stressed over losing his belongings."
A prison guard who was injured in an attack by convicted murderer Kevan Thakrar, has hit out at a court's decision to award the inmate £815 compensation for damage to his possessions, including a nose hair trimmer.
Thakrar, 26, admitted attacking the guards but a court cleared him of two counts of attempted murder and three of wounding with intent after he claimed he had been acting in self-defence.
Craig Wylde, who suffered a severed artery and damaged nerves in the attack, told the Daily Mail
It is another case of the prisoner getting everything and the real victims getting nothing.
He is always trying it on. This is the sort of person he is. He has to complain about everything and thinks he's a big man because he's challenging the system. This latest claim will have cost thousands and thousands of taxpayers' money. It is just totally pathetic."