Britain is set to signal the end of an unprecedented operation to clean up a trail of nerve agent that was left by an attack on a former Russian spy and his daughter almost a year ago.
The government is expected to announce the handover of Sergei Skripal's house in Salisbury - which was the epicentre of the novichok poisoning - to Wiltshire Council.
This would be the last of 12 sites across Salisbury and the surrounding area to be declared safe.
It can also be revealed that the armed forces are creating a new regiment specialised in tackling the threat posed by chemical, biological, radiological and nuclear (CBRN) weapons in a rebuilding of a capability that had been allowed to wither because of cost cuts.
The expansion was in part prompted by the 4 March novichok attack, which Britain has accused Russia's military intelligence agency of carrying out.