The House of Commons Foreign Affairs Committee MPs criticised the intervention by Britain and France that led to the overthrow of Libyan leader Muammar Gaddafi in 2011, when Cameron was Prime Minister.
"By the summer of 2011, the limited intervention to protect civilians had drifted into an opportunist policy of regime change. That policy was not underpinned by a strategy to support and shape post-Gaddafi Libya," the report says.
Britain and France led airstrikes on Libya after an uprising triggered by the Arab Spring. The threat of further violence by Gaddafi spurred Western powers to take action but since then thousands of people have been killed and unrest continues to this day.
The 49-page report adds: "The result was political and economic collapse, inter-militia and inter-tribal warfare, humanitarian and migrant crises, widespread human rights violations, the spread of Gaddafi regime weapons across the region and the growth of [ISIS] in north Africa.
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The criticism echoes remarks by US President Obama this year that Britain and France had not done enough to "follow up" after the conflict.
After Gaddafi was toppled, Libya descended into violence, with rival governments and the formation of hundreds of militias, while so-called Islamic State, also known as ISIL and Daesh, has gained a foothold.
Cameron has defended his handling of the situation, telling MPs in January that action was needed because Gaddafi "was bearing down on people in Benghazi and threatening to shoot his own people like rats".
The committee said there should now be an independent review of the operation of the NSC, which is chaired by the prime minister, to see if it had succeeded in addressing the weaknesses in government decision-making identified in the run-up to the 2003 invasion of Iraq.
The UK Foreign Office defended the intervention in a statement: "Muammar Gaddafi was unpredictable and he had the means and motivation to carry out his threats. His actions could not be ignored and required decisive and collective international action. Throughout the campaign we stayed within the United Nations mandate to protect civilians."
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