Iran has again denied any role in the alleged plot targeting RAF Fairford, with its ambassador to Britain, Seyed Ali Mousavi, rejecting the allegations after being summoned to the Foreign Office on Monday.

The Foreign Office said Middle East minister Stephen Doughty called in the ambassador and warned that London will not tolerate hostile Iranian activity on British soil. Iranian state news agency IRNA reported that Mousavi dismissed the allegations in categorical terms and urged the British side to avoid unsubstantiated claims.

He also said Tehran is ready to cooperate with the relevant British authorities in their investigation, and that Iran had made a similar offer before.

The meeting followed a statement to Parliament by Prime Minister Andy Burnham, who said the suspected plot was highly likely to have been coordinated in Iran and almost certainly directed by the Islamic Revolutionary Guard Corps. Britain also announced sanctions on two Iranians accused of hostile activity abroad, and one of them is reported to be a senior figure in the Guard.

The incident began on September 27, when five British men were arrested near the Gloucestershire base, which has hosted American bombers used in operations involving Iran. The men were later released on bail without charge, and the investigation is continuing.

Tehran’s denials are not new. Iran’s embassy in London rejected the accusations in September, and Foreign Minister Abbas Araghchi pointed to the release of the five suspects as proof that Britain’s case was weak. On Monday, the United States, Britain and other allies condemned Iran’s attacks and vowed action against anyone acting on Tehran’s behalf.