Tony Blair has said Isis would have acquired chemical weapons had he not stepped in to thaw the West's relations with Colonel Gaddafi.

The former Prime Minister made a staunch defence of his 2004 'deal in the desert' with the Libyan dictator, where he offered the support of Western oil companies to help extract Libya's natural resources in exchange for giving up its weapons of mass destruction.

Appearing before MPs on the Foreign Affairs Committee as part of their inquiry into the UK Government's policy towards Libya, Mr Blair argued that Gaddafi's stockpile of chemical weapons could still be in circulation had he not decided to break nearly two decades of impasse between the West and LIbya, following the 1988 Lockerbie bombing and the country's support for terrorism.

These weapons would have undoubtedly found themselves in the hands of Isis, Mr Blair said, considering the terrorist group's widespread presence in Libya since the 2011 revolution that overthrew Gaddafi.

He said the decision to bring Gaddafi in from the cold a decade ago remained "important" in the present day.

"Otherwise, we would have had a situation where Libya was continuing to sponsor terrorism, was continuing to develop chemical and nuclear weapons and would have remained isolated in the international community," Mr Blair said.

"I think it is important that we brought them in from the cold, as it were, and important also in today's context because I think - particularly if we had still had the residue of that chemical weapons programme in Libya today, given the state of Libya today and given the presence of Isis there - it would have constituted a real risk, even today."

He admitted that his decision to engage with Gaddafi had been "difficult because of the nature of the regime and the individual we were dealing with".

"But on the other hand, I think it was worthwhile, because of the protection of our security and because of the broader interest of trying to engage a country like that in a process of change," he added.

Tony Blair: A career of controversies Show all 11 1 /11 Tony Blair: A career of controversies Tony Blair: A career of controversies The Tony Blair 'selfie'.. A journalist takes a picture of Kennard Phillips 'Photo Op', depicting Prime Minister Tony Blair taking a 'selfie' in front of an explosion in Iraq, during a press viewing of the exhibition Catalyst: Contemporary Art and War Tony Blair: A career of controversies Protesters pictured outside the QEII Conference centre in London in 2011 as former British PM Tony Blair give his evidence in the Chilcot Iraq Inquiry Tony Blair: A career of controversies David Lawley-Wakelin, who disrupted Tony Blair’s testimony at the Leveson Inquiry by bursting into the court Tony Blair: A career of controversies Blair giving evidence Tony Blair: A career of controversies Tony Blair visiting troops in Iraq in 2007 Tony Blair: A career of controversies Blair meeting with troops in Basra, Iraq in 2003 Tony Blair: A career of controversies Britain's Prime Minister Tony Blair speaks to British soldiers at Divisional Headquaters in Basra, May 2007 Tony Blair: A career of controversies British Prime Minister Tony Blair eats dinner with British troops in Basra, Iraq, 21 December, 2004 Tony Blair: A career of controversies Syrian president Bashar El Assad during his official visit to the United Kingdom in 2002. Mr Blair tried to engage Mr Garcia in a conversation about Syria. The former Prime Minister made clear he was very much in favour of military intervention last summer. Tony Blair: A career of controversies Syrian president Bashar El Assad and wife Asma during their official visit to the United Kingdom in 2002. Mr Blair tried to engage Mr Garcia in a conversation about Syria Tony Blair: A career of controversies Former Prime Minister Tony Blair's signature adorns a program he signed for an Iraq veteran during a reception at the Guildhall in London following the service of commemoration at St Paul's Cathedral honouring UK military and civilian personnel who served in Iraq

Mr Blair was critical of the 2011 Arab Spring, insisting that "evolution is better than revolution".

"Who knows what would have happened if the Arab Spring had not erupted. It may have been a more peaceful evolution," he said.

The former Labour Prime Minister also revealed that he was given Mr Cameron's permission for a series of phone calls to Colonel Gaddafi in 2011, when he warned the dictator to leave Libya before French and British air strikes began, which gave rebels the cover to take hold of the country.