The Telegraph reported that Iran has used migrant-smuggling networks to send suspected intelligence operatives into Britain aboard small boats crossing the English Channel, citing unnamed Iranian officials, people smugglers and British authorities.
The newspaper reported that some individuals with alleged ties to Tehran's intelligence services were intercepted by British authorities while attempting to enter the country. It said officials have used drones and AI-equipped surveillance towers to monitor Channel crossings and identify potential threats.
The Telegraph reported that Iranian officials said some migrant-smuggling routes are controlled by the Islamic Revolutionary Guard Corps, or IRGC, and its Unit 700, the logistics branch of the IRGC's Quds Force.
One Iranian official told The Telegraph: "Of course, don't forget that our armed forces have influence and run the [smuggling] routes in some cases if they want.
"At the moment we have people right there in London, revolutionary people who care about the world and the lives of children – they wait for us to tell them what to do. We have not done that yet, but we can easily make London unsafe for you if we want to.
"These smuggling routes are more important and useful than the missiles for us – we do not need a missile to target London, it's easier than that."
The Telegraph also reported that British officials believe a greater number of people affiliated with the IRGC enter the UK legally on flights from Europe than by crossing the Channel. Officials also reportedly view the radicalization and activation of members of the Iranian diaspora, along with the use of proxies inside Britain, as a greater national security threat than small-boat crossings.
The report comes after Iran vowed to attack RAF Fairford following Britain's decision to renew permission for the United States to use the air base for operations against Iran.
MI5 Director General Ken McCallum warned in October that the agency had tracked more than 20 potentially lethal Iran-backed plots over the previous 12 months and said Tehran increasingly relied on criminal proxies to carry out operations in Britain.
Alicia Kearns, Britain's shadow security minister, called for stronger action against Iranian influence.
"The Government needs to face facts: the IRGC is exploiting the small boats crisis to put its operatives on British streets.
"We need an urgent taskforce to root out Iranian agents among those arriving and who've arrived on our shores, designation of the Ministry of Intelligence and Security under hostile state legislation, and emergency powers to shut down IRGC cut-outs like the Islamic Centre of England.
"Tehran is openly threatening Britain and we have a Prime Minister silent on our national security – our people deserve answers, action and leadership."
Dr. Kristian Gustafson, deputy head of Brunel University's Centre for Intelligence and Security Studies and a former Sandhurst lecturer, told The Telegraph Tehran would more likely recruit individuals already living in the UK than bring in its own operatives through illegal migration routes.
A Home Office spokesman said Britain conducts stringent security checks on small-boat arrivals and detains anyone identified as a national security threat. He said the government has expanded the powers of police and intelligence agencies to disrupt those working on behalf of the IRGC and make it easier to prosecute them.