The Syrian regime has accused Boris Johnson of being "completely dissociated from reality" after the foreign secretary hosted Syrian opposition leaders in London to discuss their plans to end the country's civil war.

Mr Johnson endorsed a blueprint for the future released by the High Negotiations Committee (HNC), an umbrella opposition group, which called for the Syrian regime leader Bashar al-Assad to give up power as part of a political transition.

The foreign secretary said the plan was "a formidably important document" and said Mr Assad could play no role in Syria's future once the six-month transition period was finished.

Mr Johnson's words and his decision to host the opposition group at the Foreign Office drew a furious response from the Assad regime in Damascus.