"Cameron and his government must leave after the popular uprising against them and the violent repression of peaceful demonstrations by police," official news agency Jana quoted Deputy Foreign Minister Khaled Kaaim as saying.
"Cameron and his government have lost all legitimacy," he said.
"These demonstrations show that the British people reject this government which is trying to impose itself through force."
Kaaim called on the UN "Security Council and the international community to not stay with its arms crossed in the face of the flagrant violation of the rights of the British people".
Nightly riots which began in London and quickly spread to other major cities have gripped Britain since Saturday when an angry crowd marched to demand justice after 29-year-old Marc Duggan was shot dead by police in London.
Britain and France are spearheading Nato's aerial bombing campaign against the Gaddafi regime since March, when the United Nations approved action to protect Libyan civilians.