Speaking at an event hosted by Prospect magazine, the mastermind of Britain’s involvement in 2003 invasion of Iraq reiterated his call for greater military involvement in the conflict.
“If you want to defeat these people, you're going to have to go and wage a proper ground war against them,” he said.
The former Labour Prime Minister said it was important that Libya was not ceded to the militant group, and that if they were not dealt with “they will come and attack us here”.
"We cannot afford to have Isis govern a large part of Libya – we shouldn't be in any doubt they need to be taken on on the ground,” he said.
Ground forces currently fighting Isis in the Levant are mostly Kurdish, Iraqi government, Syrian government and other militant groups.
In Libya, where the group controls the central port city of Sirte, domestic Libyan forces have contained its advances beyond that area.
The UK is currently involved in a coalition of nations conducting airstrikes against the so-called Islamic State in Syria and Iraq.
Isis has been losing ground in the Levant in recent months, with Iraqi government forces now advancing on the city of Fallujah, which the group holds.
Mr Blair has previously called for Western ground forces to be used against Islamist militant groups. In an article for The Sunday Times in March he said they were “necessary” to beat Isis.
“We must build military capability able to confront and defeat the terrorists wherever they try to hold territory,” he wrote at the time.
“This is not just about local forces. It is a challenge for the West. Ground forces are necessary to win this fight and ours are the most capable.”
Mr Blair is reportedly expected to be criticised in the Chilcot Report into the events of Iraq War, which is due out in July after years of preparation and analysis.
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