Forme colonel Philip Ingram claims the Glasgow climate change conference, which starts next Sunday, will be a “very ripe target” for terrorists with “high potential” for an attack.
World leaders, including US president Joe Biden, are set to jet into Glasgow, along with thousands of business representatives, activists and protesters for the summit at the city’s SEC.
Security fences and CCTV cameras have been erected around the COP26 venue.
Mr Ingram said Police Scotland would be backed up by armed SAS officers, security service personnel and counter-terrorism teams for the duration of the climate conference.
He said: “It will not just attract Islamist terrorists, it’s good for right-wing terrorists, the extreme left and for eco-terrorists – it is a big target, a very ripe target, and the potential for an attack is high.
“From the contingency planning perspective, this will be beyond the capability of Police Scotland. In the background, you will have the security service with surge capability.
“Anyone on the terror watchlist – as of today there are probably 800 active investigations into people who could be preparing attacks – the security service will have maximum capability to watch for any indications they might be moving towards threatening CO26.
“Backing that up there will be support from the MoD [Ministry of Defence], with special forces allocated to reinforce the police.”
Police Scotland said policing COP26 would be the force’s biggest challenge to date.