Britain’s Prime Minister Andy Burnham was urged on Monday to take direct action against Iran if it succeeded in attacking a British airbase.
The UK announced sanctions against two Iranian nationals who the government said had been involved in Iranian plots to attack Britain, which Mr Burnham blamed on Iran’s Islamic Revolutionary Guard Corps.
He was told by former deputy prime minister Oliver Dowden that Iran considered the UK its enemy and “smells weakness”.
He said Iran had attempted attacks at bases in Diego Garcia in the Indian Ocean, Akrotiri in Cyprus and Fairford in Gloucestershire.
The UK introduced sanctions on the IRGC in July, following the first two incidents and a series of attacks against dissidents in previous years.
A successful attack would require direct action, suggested Mr Dowden, who also asked for a pledge of “enhanced support and assistance to allies under constant attack”, noting the targeting of Saudi Arabia in recent days.
Mr Burnham said Britain was providing the “most robust response” to the situation and “playing its part”.
Under Monday’s sanctions, the head of counter-espionage operations within the IRGC, Ruhollah Bazghandi, will be subject to an asset freeze, travel ban and prevented from running any companies in the UK.
The government believes he was directly involved in threatening, planning or conducting attacks against in the UK or against its allies.
A key organiser of the Zindashti criminal network, Shahram Ali Reza Tamarzadeh Jakki, who the government said had been involved in several plots against Iranian dissidents, has also been sanctioned for supporting planned attacks.
Foreign ministries from almost 30 countries including the US, Canada, France and Germany issued a statement condemning "Iran’s use of violent attacks, including the acts of lethal plotting, arson, sabotage, cyber-attacks, and other hybrid activities against us and our partners".
"The UK has also concluded this event demonstrates the IRGC’s continued willingness to project hostile activity beyond its borders through covert networks and proxy actors," the statement said.
The developments were announced as Mr Burnham told the House of Commons that it was highly likely that the incidents at RAF Fairford, an airbase used by the US to launch attacks on Iran, were co-ordinated in Iran, almost certainly directed by the IRGC.
Seven men have been arrested, and released, over a suspected attack on the base in Gloucestershire. Police said petrol but no viable explosive had been found in vans near the base, and detectives said they were considering whether a foreign state had been involved.
The US decided to remove its B-1 bomber aircraft from the base after the attack, giving mixed messages over whether there had been direct intelligence of a plot to carry out a drone attack, or whether it had been done out of caution.
Increasing danger
The British authorities have accused Iran of being involved in numerous plots in Britain.
In July, Britain used new powers designed to stop the use of state-sponsored proxies to ban support for the IRGC and a linked group accused of being behind attacks at locations linked to Jewish and Israeli communities and Persian-language media.
Mr Burnham said: “We will not tolerate these threats on our soil. We will crack down on Iran’s use of criminal networks using our full range of powers to target them and their funding streams. And we will bring further sanctions to restrict the capacity if Iran and the IRGC to do us harm.”
Foreign Secretary Ed Miliband said Iran’s continued attempts to undermine the security of the UK and its allies “through its criminal networks, proxy groups and state-backed malign activity is unacceptable”. The Iranian ambassador was summoned for a foreign office dressing down but the Tehran state news agency afterwards described the British allegations as baseless.
Iran's Ambassador to Britain, Seyed Ali Mousavi, denied any Iranian role in a suspected plot, saying Tehran was willing to cooperate with British authorities in investigating the issue.
“We are also announcing the designation of two Iranian nationals for their role in facilitating or engaging in hostile activity on behalf of the Iranian regime, with the clear intent of threatening, planning or conducting attacks overseas," Mr Miliband said.
“This government will never waiver in our commitment to tacking Iran’s unacceptable actions and protecting our national security. We have already designated the IRGC under our new state threats powers, and imposed major sanctions on those responsible for Iran's malign activity.”
The Foreign Office said the UK had identified at least 15 credible Iranian-backed threats to kill or kidnap individuals in the UK between 2022 and 2023, rising to more than 20 in 2025.