Iran’s ambassador to the UK has been ordered to return to Tehran and is to be removed from his post after a video emerged showing a reception at the embassy during which some women did not have head covered.

News of Mohsen Baharvand’s return to Tehran was reported by Iranian news agency ILNA.

At the event commemorating Iran’s 43rd revolution, a woman playing the piano alongside a violinist was not wearing a hijab. Another video from the event showed a more conventional gathering at which speeches were made.

An Iranian in London tweeted a video of the event, which was largely attended by diplomats, asking if the party would have “with the presence of these people any benefit to the Iranian people?” He then tweeted: “It is gratifying that our voice has been heard in Iran. Please send an ambassador to London who is pragmatic and worthy of serving Iran and working only for the benefit of the Iranian people.

The news first circulated in pro-regime newspapers, and some claimed it was part of a wider reorganization of Iran’s diplomatic service led by the new, more radical government led by Ebrahim Raisi, elected last June.

Baharvand was appointed by the Foreign Office ahead of presidential elections, but took up his post in London in July after the department’s leadership changed. He was previously deputy head of the legal department in Iran under Mohammad Javad Zarif, the former foreign minister.

In his dealings with journalists in the UK, the ambassador did not deviate from the government’s official position on the Iranian nuclear talks, but attempted to explain the background to Iranian thinking.

His departure comes at a critical moment in Anglo-Iranian relations. Iran is set to decide whether to accept Washington’s terms for a US return to the Iran nuclear deal, including the lifting of numerous sanctions. Along with the nuclear talks, Britain is seeking the release of three British-Iranian nationals held in Iran.

The Islamic Consultative Assembly, Iran’s parliament, met in private session on Sunday to review the status of talks that many believe could finally come to a conclusion this week. Ali Bagheri, Iran’s chief negotiator, is due to return to Vienna, where talks on Iran are taking place, on Sunday with new final instructions. Iranian Foreign Minister Hossein Amir-Abdollahian is due to meet Iran’s Supreme National Security Council on Monday, and there is talk of a special session of the Iranian parliament on Tuesday.

The foreign minister said the talks were continuing, stressing that nothing was agreed until everything was agreed. Issues remain over assurances of the US’s long-term commitment to the deal and the extent of the suspension of sanctions.

Both sides appear to be trying to keep the fallout from Russia’s invasion of Ukraine from spreading in the critical final days of the Vienna talks.

Russia, as a signatory to the Joint Comprehensive Plan of Action – the technical term for the 2015 agreement – ​​acted as a key mediator in the months-long talks in Vienna between European powers, the United United and Iran. The Russian ambassador in Vienna, Mikhail Ulyanov, was a strong supporter of the invasion.

Opponents of the deal, who are not necessarily parties to the negotiations, fear that a deal will give Iran leeway to become a nuclear power relatively quickly and argue that the West’s experience with Russia shows that appeasement of fundamentally hostile powers does not work and only emboldens them.

Some Iranian political scientists have urged Iran not to be too outspoken in its support for Russia, fearing it will make it more difficult for the Biden administration to garner political support for the deal. But Ali Shamkhani, the secretary of Iran’s Supreme National Security Council, said the war was the direct responsibility of the West’s willingness to threaten the security of other countries.

Amir-Abdollahian also criticized NATO provocations without condoning violence. Iran views the era of Cold War blocs as over and America in long-term decline, but it is important for Iran to follow an independent path and not become a client from China.