Nazanin Zaghari-Ratcliffe: Iran-bound Boris Johnson hopes to make progress on release

Boris Johnson lands in Tehran later for his first visit to the Iranian capital hoping to make progress towards securing the release of jailed British mother Nazanin Zaghari-Ratcliffe.

The focus of the trip is to build stronger relations with Iran, strained since 2011 when an Iranian mob ransacked the British Embassy in Tehran.

But it has personal importance for the Foreign Secretary's career after a mistake he made regarding Mrs Zaghari-Ratcliffe in front of MPs last month.

The UK government has always insisted the dual national British-Iranian was on holiday in the country when she was arrested in April 2016. She had gone there to introduce her 21-month-old baby daughter to her Iranian parents.

The Foreign Secretary mistakenly said she had been there training journalists. Iranian state media leapt on the gaffe and presented it as evidence she had been lying about the true nature of her visit.

Mr Johnson eventually apologised for the blunder and promised to use a long-planned visit to Iran to make amends. He now has his opportunity.

There is though little sign of a breakthrough in efforts to secure Mrs Zaghari-Ratcliffe's release and concerns continue to mount about her condition in jail. She has suffered chronic depression since her incarceration.

En route to Iran, Mr Johnson said he will be pressing her case and others like her being held in Iranian jails, promising to "stress my grave concerns about our dual national consular cases and press for their release where there are humanitarian grounds to do so".

He indicated though that the visit will be dominated by more geopolitical issues, "including how we can find a political solution to the devastating conflict in Yemen and secure greater humanitarian access to ease the immense suffering there. I will also underline the UK's continued support for the nuclear deal while making clear our concerns about some of Iran's activity in the region".

The UK government says there is no reason for Mrs Zaghari-Ratcliffe's detention.

The evidence presented in court has been obscure and sketchy. Mrs Zaghari-Ratcliffe, from Hampstead, has been charged with trying to topple the Iranian government.

The Foreign Secretary's visit coincides with a new report presenting shocking new evidence of the widespread use of torture in Iranian jails.

Campaign group Freedom From Torture catalogues what it calls "appalling physical abuses, from beatings and stress positions to electric shocks and cutting with knives, as well as high levels of sexual violence perpetrated against men and women, including rape".

Discussions with Mr Johnson's Iranian counterpart Javad Zarif are also likely to include Iranian concerns about the legacy of sanctions on the country, lifted since the Iranian nuclear deal was signed with the West, but not leading they say to adequate relief on the country's economy.

Iran also wants progress on the repayment of more than £300m owed for a pre-Iranian revolution order for Chieftain tanks from the UK, still held up in an interminable legal process.

And Britain seeks a broader diplomatic relationship with Iran after the normalisation of relations following the nuclear deal.

The plight of Mrs Zaghari-Ratcliffe remains a festering sore in Iranian British relations as do the cases of others being held in Iranian jails.