The UK government has welcomed the conviction by a Baghdad court of former Iraqi President Saddam Hussein for crimes against humanity.
Foreign Secretary Margaret Beckett, said all the defendants were being held to account for their crimes.
Shadow foreign secretary William Hague said the verdict should be "respected".
Liberal Democrat leader Sir Menzies Campbell warned that executing the former leader could make him a martyr and he should be imprisoned for life.
Mrs Beckett said: "I welcome that Saddam Hussein and the other defendants have faced justice and have been held to account for their crimes.
"Appalling crimes were committed by Saddam Hussein's regime. It is right that those accused of such crimes against the Iraqi people should face Iraqi justice.
"Today's verdict and sentences by the Iraqi Higher Tribunal come at the end of a trial during which evidence has been offered and challenged in the full glare of media scrutiny."
Home Secretary John Reid said the UK should respect the Iraqis' decision.
Mr Reid said: "It [the verdict] was an achievement for Iraq and an ultimate expression of their own sovereignty."
He added that they are "masters of their own destinies".
Mr Hague said: "We congratulate the Iraqi courts on reaching a verdict in such difficult circumstances, and the bravery shown by judges and witnesses in the face of severe violence and intimidation.
"The verdict and sentencing of Saddam are a matter for Iraqi law and the Iraqi people, but they deserve the support of the international community in ensuring that the decisions reached by the court are respected."
He would not be drawn on whether he agreed with the death penalty decision.
Margaret Beckett said his regime committed "appalling crimes"
He said: "It is a sovereign decision taken by a sovereign nation, it is the ultimate expression of the sovereignty of Iraq."
He added that it was a decision "which all of us should respect".
Liberal Democrat leader Sir Menzies Campbell said: "The conviction of Saddam Hussein will bring relief to countless Iraqis whose lives have been blighted by the enormity of his behaviour.
"But it will not bring back the many thousands who perished while he ruled their country.
"His martyrdom can only add to the instability and unrest in Iraq. He should be detained for the rest of his natural life."
Anas Altikriti, the British Muslim Initiative spokesman, said the "sad reality" was that the verdict could mean the Iraqi people would "never have their day in court".
Saddam Hussein, former Iraqi president: found guilty and sentenced to death
Barzan Ibrahim al-Tikriti, Saddam Hussein's half-brother: found guilty and sentenced to death
Awad Hamed al-Bandar, Chief Judge of Revolutionary Court: found guilty and sentenced to death
Taha Yasin Ramadan, former Iraqi vice-president: found guilty and sentenced to life in jail
Abdullah Kadhem Ruaid Senior Baath official: found guilty and sentenced to 15 years in jail
Abdullah Rawed Mizher, Senior Baath official: found guilty and sentenced to 15 years in jail
Ali Daeem Ali, Senior Baath official: found guilty and sentenced to 15 years in jail
Mohammed Azawi Ali, Baath official: acquitted
"If he was indeed executed before the Iraqi people could find out what really happened over the last 30 or 40 years that would be another great tragedy," he said.
Scottish National Party (SNP) leader Alex Salmond - a longstanding critic of the government's military campaign - said it was a "very understandable verdict given the terms of the court".
Dr Muhammad Abdul Bari, secretary general of the Muslim Council of Britain, said there had been concerns about whether Saddam would receive a fair trial in Iraq "given the sectarian tensions that are rife".
"We stated at the outset we preferred for him to be tried in an international court," he added.
"There will be many in the Muslim world who will be asking when those responsible for launching the calamitous war in Iraq, in which tens of thousands on innocent people have died, will also be brought to justice."