Linking the major shake-up to the Salisbury nerve agent attack blamed on the Kremlin, the Prime Minister will announce a ‘Fusion Doctrine’ to counter Vladimir Putin’s ‘hybrid tactics’ as well as Islamist terrorism with a full range of resources, from military deterrence to economic sanctions and cyber warfare.

“Over the past year in the UK we have witnessed appalling terrorist attacks in London and Manchester, but also a brazen and reckless act of aggression on the streets of Salisbury,” Mrs May says in the foreword to the National Security Capability Review unveiled today.

“Crucially, what all of these incidents have made clear is that our national security is conditional on not only the police and security services who work so hard to keep us safe at home, or on the brave men and women of our armed forces working tirelessly around the world – but on our ability to mobilise most effectively the full range of our capabilities in concert to respond to the challenges we face.”

New investment in a £1.9 billion cyber security strategy announced earlier this year will see the team dedicated to combatting misinformation from hostile states like Russia expanded.

A National Economic Crime Centre is also being created to crack down on the money laundering that supports foreign criminal networks, including Russian oligarchs with ties to the Putin regime who shelter their assets in London.

More resources will be put into the UK’s network of embassies and high commission to strengthen Britain’s ability to project soft power.

“Based on the new Fusion Doctrine, this approach will ensure that in defending our national security we make better use of all of our capabilities: from economic levers, through cutting-edge military resources to our wider diplomatic and cultural influence on the world’s stage,” Mrs May adds. “Every part of our government and every one of our agencies has its part to play.

“As long as we defend our interests and stand up for our values, there will continue to be those who seek to undermine or attack us. But these people should be in no doubt that we will use every capability at our disposal to defeat them.”

Sergei Skripal and his daughter Yulia remain in critical condition in the hospital in Salisbury and “may never recover fully”, the Prime Minister has warned.

Russian Deputy Foreign Minister Sergei Ryabkov told the RIA Novosti news agency that the expulsion of more than 130 diplomats by western allies “will be met with a tough response”. Belgium and Ireland became the latest countries to expel diplomatic staff. International security organisation Nato also said it would deny pending accreditation for three Russian staff, and would reduce the size of Russia’s mission from 30 to 20.

At a meeting of the cabinet yesterday, Mrs May has hailed the “unprecedented series of expulsions”, saying it sent a strong message to Moscow that it cannot ignore international law.

Nato Secretary General Jens Stoltenberg told reporters in Brussels the moves sent a clear message to Russia that its actions “had costs”.

He added: “What triggered this was the Salisbury attack. But it is part of a broader response by Nato allies to a pattern of unacceptable and dangerous behaviour by Russia. We have seen the illegal annexation of Crimea, we have seen the destabilisation of eastern Ukraine, we have seen cyber attacks, we have seen hybrid tactics, we have seen Russia investing heavily in modern military equipment and the willingness to use military force against neighbours.”

Theresa May: UK will use '˜every capability at our disposal' to defeat enemies