The IRGC has now been sanctioned by the UK and will be subject to asset freezes but has not been fully proscribed.
Britain has also penalised Naji Ibrahim Sharifi-Zindashti, who is allegedly the head of an international drug smuggling and human trafficking cartel run by Tehran.
Foreign Secretary David Cameron said: “The Iranian regime and the criminal gangs who operate on its behalf pose an unacceptable threat to the UK’s security.
“Today’s package exposes the roles of the Iranian officials and gangs involved in activity aimed to undermine, silence, and disrupt the democratic freedoms we value in the UK.
“The UK and US have sent a clear message – we will not tolerate this threat.”
Home Secretary James Cleverly said: "The Iranian regime has tried to undermine our democracy through repression – we will continue to take action when necessary to protect our country, values and freedom of speech.
“We cannot allow foreign regimes to collaborate with criminals to threaten us. Sanctioning these criminal networks working for the Iranian regime will remind them that we will fight back.
“My priority is to protect our people and to defend our way of life, and the UK will not tolerate threats from the Iranian regime.”
