While Iran continues to deny its involvement, Liam Fox, the former UK defense secretary, has accused Iran of orchestrating its proxy Hamas's war on Israel.

"If the fingers on the trigger were Hamas’s, the strings were being pulled from Tehran," he said, calling for the UK to designate the Islamic Revolutionary Guards Corps (IRGC) which controls Iran's many proxies across the region.

The UK's counter-extremism commissioner, Robin Simcox, also had a similar stance, saying that continued legal support for the IRGC would not be sustainable. The IRGC has been designated as a foreign terrorist organization (FTO) by the US State Department since April 2019, but the UK has yet to do so.

Fox criticized the UK for failing to list the IRGC as a terrorist group, despite the fact that "£100 million of investment goes from Tehran to Hamas terrorists" annually and called for closing Iranian banks that operate from the City of London and stopping Iran Air flights from Heathrow.

The UK has imposed sanctions on Iranian individuals and entities since Mahsa Amini's death in September 2022 as a response to human rights violations committed by the regime's IRGC forces. But, proscription would have made belonging to the group, funding it, or expressing support for its activities in the UK criminal.

The British government exacerbated sanctions, pledging to step up protection for Iranian journalists based in the United Kingdom, following the suspension of Iran International's UK operations due to continued threats to its employees and based on advice from the London Metropolitan Police.

The Iranian government has repeatedly threatened Iran International and other Persian broadcasters based abroad.

The refusal to proscribe the IRGC has caused sharp political criticism, as the opposition Labour Party calls for its proscription under the 2000 Terrorism Act.