The world is facing a dangerous proliferation of deadly chemical weapons in the wake of the Salisbury poisonings, Defence Secretary Ben Wallace has warned.

Three years on from the attempted killing of former spy Sergei Skripal using a novichok nerve agent, Mr Wallace said it was clear that Russia remained an “adversary” of the UK.

He said Moscow’s willingness to use a banned chemical weapon on British streets represented a challenge to international law and the world order.

At the same time, capabilities which were once the sole preserve of states are becoming ever more widely available, posing a further threat to global stability.

“We can’t take anything for granted in the way we maybe did in the Cold War when there was a nice, static and fairly sterile relationship with a fence down the middle of Europe,” Mr Wallace told the PA news agency.

“What I worry about is when people have disregard for the international rule of law and domestic rule of law and those people are no longer purely terrorists/organised criminals but other states.

“It challenges many of the values we stand for and it challenges the world order. That is something that should worry us all.”

Mr Skripal, a former Russian intelligence officer turned double agent for MI6, and his daughter, Yulia, were left fighting for their lives after the handle of his front door was coated with novichok.

A policeman who attended the house was also admitted to hospital.

Potentially hundreds of people's lives were put at risk given the weapon that was used

Four months later, 44-year-old Dawn Sturgess died after apparently picking up the discarded bottle used to contain the nerve agent.

The Government subsequently identified two officers in Russia’s GRU military intelligence who, it said, were suspected to have carried out the attack.

“Dawn Sturgess lost her life as a result of this attack and potentially hundreds of people’s lives were put at risk given the weapon that was used,” Mr Wallace said.

“It reminded the West that countries purporting to be world leading countries have a disregard sometimes for international law and sovereignty and seek to deploy some of the worst weapons on our streets.

“I remember the gasps in Parliament when the Prime Minister (Theresa May) stood up and announced that we had identified GRU officers acting on behalf of the state. That was a sobering moment for many.

“The lesson from that has been that Russia is, I’m afraid, an adversary.”

Mr Wallace said that Moscow had deployed a “spectrum” of capabilities in its campaign against the UK and the West, from cyber attacks to the use of “proxies” like the Wagner Group mercenaries.

“Some of those things we see in the daylight, so to speak, and some of those things I can’t really talk about, we see in the shadows,” he said.

At the same time, as the world order “loosened,” Mr Wallace said there were new opportunities for non-state actors.

“Now you can find out how to make chemical weapons on the internet,” he said.

“That proliferation means that many people in the world have access to knowledge that can turn what might be ambitions into realities, around everything from conventional attacks to CBRN (chemical, biological, radiological, nuclear) capabilities.”

Mr Wallace acknowledged there was little immediate prospect of the suspected perpetrators being brought to trial, but said the Government would not give up hope that they would one day face justice.

“If they have been given the shelter of a state it is quite a hard problem. I don’t bear much hope that the Russians will grant an extradition for some of the individuals to us any time soon,” he said.

“We have been clear who we think are the suspects wanted in relation (to this matter) for questioning. I don’t think that has gone away, that desire to deal with those issues.”