‘Gravest consequences’ for intervention, says Moscow

some in his administration, even while approving a series of sanctions against Kremlin allies.

Russia, which along with Iran is supporting the Assad regime, yesterday denied chemical weapons had been used in the attack and warned against a military response.

The Russian foreign ministry said: “The goal of these false speculations, which are not substantiated by any facts, is to cover up terrorists and irreconcilable radical opposition, which opposes political settlement, and to simultaneously try to justify potential external military strikes.

“It is necessary to once again caution that military intervention under false and fabricated pretexts in Syria, where the Russian servicemen stay at the request of the legitimate government, is absolutely unacceptable and may trigger the gravest consequences.”

Iran’s foreign ministry called claims of chemical weapons use “an excuse” for a military attack.

Syria’s foreign ministry said such allegations were an “unconvincing broken record”.

Boris Johnson, the Foreign Secretary, said that Britain was in close touch with the US and other allies, adding that those behind the attack must be “held to account”.