The UN special rapporteur on Iran has expressed solidarity with the Iranian hunger striker who has camped outside the British Foreign Office for 44 days.

Javaid Rehman, the UN human rights rapporteur, Friday visited Vahid Beheshti who has been campaigning for the UK to proscribe the Islamic Revolutionary Guard Corps.

Beheshti has been battling the bitter winter outside the UK Foreign Office to raise awareness for the need to designate the IRGC responsible for the deaths of hundreds of Iranian citizens since September.

In his third letter on Monday the British prime minister, he reiterated his desire to meet PM Rishi Sunak, adding that “my body grows ever weaker, yet internally, I grow ever stronger in my conviction that this is the right thing to do.”

Beheshti called his request to the British government "simple and at the same time, very important" emphasizing the urgency of proscribing the IRGC.

He said the designation urgently needs to happen, not only for the people of Iran who yearn for democracy, but also for the people of Britain and "the values we uphold".

“As long as we continue with our appeasement policy, the IRGC will continue with their hostage taking policies,” he said. “They only understand one language, pressure and strong leadership.”

Beheshti has not eaten since February 23 and lost a large amount of his body mass. In the past days, a group of other Iranians also joined him and set up tents next to him.