The UK’s ambassador to Iran has returned to London for talks amid increased diplomatic tensions between the two countries.

Rob Macaire has been labelled “persona non grata” by Iran’s judiciary and an effigy of the envoy was burned in Tehran by hardline protesters.

The Foreign Office sought to play down the significance of his trip to London, with sources insisting it was a planned visit for talks and he would return to Tehran.

The ambassador was arrested and briefly detained on Saturday after attending a vigil for the 176 people, including four Britons, killed when Iran accidentally downed a Ukrainian jet.

Iran
Pro-government protesters set fire to a life-size cut-out of Britain’s ambassador Rob Macaire (Vahid Salemi/AP)

The vigil turned into a protest, although Mr Macaire said he left after five minutes when some of those present started chanting.

Iranian media reported that judiciary spokesman Gholam Hossein Esmaeili said Mr Macaire had not respected the nation’s laws and should be expelled.

“Under international law, such a person is a ‘persona non grata’,” Mr Esmaeili told reporters.

“The (Iranian) people expect the person to be expelled and that is also what international law calls for.”

Whitehall sources insisted his visit was routine and he would use it as an opportunity to brief officials and Foreign Secretary Dominic Raab.

The Foreign Office said it was “very much business as usual”.

A Foreign Office spokesman said: “Ambassador Rob Macaire is returning to the UK today on a long-planned visit.

“He will have a number of meetings while in the UK and this is very much business as usual. He will be returning to Iran in the coming days.”

The latest developments come after the UK, France and Germany began action against Iran over its failure to comply with the terms of the nuclear deal.

Prime Minister Boris Johnson suggested that Donald Trump could produce an alternative nuclear deal after the current accord was undermined by the US withdrawal from it.

The US president responded on Twitter, saying he agreed that a “Trump deal” was the way forward – although so far Washington has yet to produce any alternative to the Joint Comprehensive Plan of Action (JCPOA) agreement.

Meanwhile, an imprisoned British-Australian woman begged Australian Prime Minister Scott Morrison to help secure her release from an Iran jail.

Cambridge-educated Kylie Moore-Gilbert, who was most recently a lecturer in Islamic studies at Melbourne University, has been in Tehran’s notorious Evin prison for more than a year, having reportedly been given a 10-year sentence.

“I beg of you, Prime Minister Morrison, to take immediate action, as my physical and mental health continues to deteriorate with every additional day that I remain imprisoned in these conditions,” she said.