Boris Johnson has refused to apologise for putting Nazanin Zaghari-Ratcliffe at risk of an extra five years in prison, insisting he is not to blame.

The Foreign Secretary claimed there was no “connection” between his incorrect statement – that the British charity worker was “teaching journalists” – and the fresh spying charges levelled in Iran.

The stance, in the Commons, came despite the Iranian judiciary seizing on Mr Johnson’s gaffe as evidence that Ms Zaghari-Ratcliffe was not, as she insisted, on “holiday”.

There were shouts of “disgrace” as Mr Johnson rebuffed repeated calls for him to apologise and acknowledge his mistake, made in evidence to MPs last week.

Instead, he told Emily Thornberry, Labour’s Shadow Foreign Secretary: “It is simply untrue for her to say, as she has said today, that there is any connection whatever between my remarks last week and the legal proceedings under way against Nazanin Zaghari-Ratcliffe in Tehran today,”

Mr Johnson said criticism of him “deflects accountability from those who are truly responsible for holding that mother in jail and that is the Iranian regime”.

Eventually, after almost one hour of questioning, he added: “I'm sorry if any words of mine have been taken out of context and misconstrued to cause anxiety to Nazanin's family.”

Mr Johnson faced MPs after hurriedly speaking with his Iranian counterpart, Mohammad Javad Zarif, about Ms Zaghari-Ratcliffe’s case.

The Foreign Office insisted he was told the new charges of spreading “propaganda” – and the new five-year prison threat, on top of an existing five-year sentence – “were unrelated to the Foreign Secretary’s remarks.”

But the Iranian judiciary’s High Council for Human Rights wrote: “His [Mr Johnson’s] statement shows that Nazanin had visited the country for anything but a holiday.”

Mr Johnson – giving a statement about Daesh, rather than Ms Zaghari-Ratcliffe’s plight – insisted he had been arguing that, even if she was training journalists, that would not have justified her detention.

But, in fact, speaking to the Commons Foreign Affairs Committee, he had said: “When I look at what Nazanin Zaghari-Ratcliffe was doing, she was simply teaching people journalism as I understand it.”

The 38-year-old was separated from her 21-month-old daughter Gabriella when she was arrested as she tried to return home to London in April 2016.

Gabriella, now three, remains at the Tehran home of Nazanin’s parents, while her mother is in a high-security Iranian jail and her father in London.

Ms Thornberry said Mr Johnson should apologise to Ms Zaghari-Ratcliffe, her family and everyone “who have been working so hard to obtain this young mother's release for the distress and anguish that his foolish words have caused”.

She added: “How many more time does this need to happen? How many times does the Foreign Secretary have to insult our international partners, damage our diplomatic relations, and now imperil the interests of British nationals abroad?

"What will it take before the Prime Minister says enough is enough?”

Labour's Tulip Siddiq, Ms Zaghari-Ratcliffe's North London MP, pointed out that a year had gone by without Mr Johnson meeting Ms Zaghari-Ratcliffe’s husband, Richard.

And Chris Bryant, another Labour MP, said his failure to be open about his mistake would be obvious to every “single eight-year-old in the country”.

“The honest truth is if you can't show some contrition today then the honest truth is he shouldn't be in his job as our people aren't safe,” Mr Bryant added.

Anna Soubry, a Conservative, described the blunder as “appalling”, saying: “In "normal" times Boris Johnson would have been sacked long ago.”