Nerve agent
Government still blames Russia for attack.
The diplomats are due to fly to Moscow on Russia's national carrier.
'There is no other conclusion' but Russia's culpability, May said.
Reports come from US media.
All you need to know from the Sunday politics shows
Freshly-elected president says Russia does not possess nerve agent used in attack.
Tests to begin 'imminently'.
Is it just me, or are too many people still refusing to see what is staring them in the face? Someone is waging war on the West
MP asks: 'Why is BBC giving a platform to a mouthpiece for Putin?'
I can’t work out why so few people seem able to hold both of these opinions at once