Richard Ratcliffe has cautioned the government that there are "lessons to be learned" from his wife Nazanin Zaghari-Ratcliffe's six-year incarceration in Iran after she and her family encountered Boris Johnson this afternoon.
Ms Zaghari-Ratcliffe, who was set free in March after the UK concerted to resolve a £400m deficit with Tehran as far back as 1979, was chaperoned to the assembly in Downing Street by her husband Richard and their daughter Gabriella.
Other Foreign Office office holders were also present at the assembly which was the first Ms Zaghari-Ratcliffe has had with the PM since her comeback to the UK.
Speaking in Downing Street after the assembly Mr Ratcliffe informed newscasters: "It was two years ago that I stood here having seen the prime minister and I came out fairly forlorn, in the sense that we were having to battle for longer.
"I stand here now with the battle over for us.
"I think there are lessons to learn, there is a wider problem.
"We talked about the mistakes made at the end. It was rough at the end, and I think, when Nazanin is ready to talk about it, that is something that we need to go through.
"But no, I think, it is not like when this is over that you feel angry. Relief is what I honestly feel."
Mr Ratcliffe added: "I don't think it was an abrasive meeting."
Labour's Tulip Siddiq, Ms Zaghari-Ratcliffe's constituency MP, was among those that attended the assembly with the family.
Thereafter, Siddiq said Ms Zaghari-Ratcliffe informed Mr Johnson she feels "guilty" that she is back in Britain when others remain in the "same conditions that she went through" in Iranian prisons.
"We raised Morad Tahbaz and also raised the case of a man who is on death row who is from Sweden, because the prime minister has just come back from Sweden, and we said that the pressure has to be kept up," the Labour MP said.
"Nazanin kept making the point that people who went in quite soon around the time that she went in, they are not home yet and she is home and she feels very guilty about that.
"She wants them to be back as well and she can't sit here and enjoy her life knowing there are people going through the same conditions that she went through.
"And she talked a bit about what she went through when she was actually in jail and it was quite difficult to hear actually.
"It is not like I don't know the details but to hear it again quite in the manner she was laying it out was quite difficult to hear."
Ms Siddiq added that the PM looked "quite shocked" when Ms Zaghari-Ratcliffe told him she had lived in the "shadow of his words" for "the best part of four-and-a-half years".
Ahead of the assembly, the PM's pointperson said: "We've said previously that the prime minister was open to meeting both Nazanin as well as Mr (Anoosheh) Ashoori.
"It is something we have been trying to arrange. I've set out that he is going to welcome her to Downing Street to discuss her ordeal in Iran."
The office holder said the assembly was "something we've worked together on to make happen".
In 2017, Mr Johnson inaccurately informed MPs that Mrs Zaghari-Ratcliffe had been "teaching people journalism" before her detainment by Iranian authorities.
Mrs Zaghari-Ratcliffe's family and her employer have both asserted that Mr Johnson's remarks were erroneous.
Richard Ratcliffe informed Sky News that the PM didn't atone.
Asked whether the PM would be making amends to Ms Zaghari-Ratcliffe, the mouthpiece replied: "I think it is important to remember that it was the Iranian government who were responsible for her unfair detention, and the decision to release her was always in their gift.
"However, I would point back to the prime minister's words, his answers to questions on this before and he has previously apologised for his comments in 2017."
Ms Zaghari-Ratcliffe has been critical of the inability of the Foreign Office to secure her freedom sooner.
In a news conference in March after her return to the UK, which saw her reunited with her husband Richard and daughter Gabriella, the former captive said "what happened now should have happened six years ago".
She said: "I was told many, many times that 'oh, we're going to get you home'. That never happened.
"How many foreign secretaries does it take to get someone home? What happened now should have happened six years ago."
She added that the "meaning of freedom is never going to be complete" until Morad Tahbaz and other dual nationals who have been held in Iran are released.
Former foreign secretary Jeremy Hunt safeguarded Ms Zaghari-Ratcliffe after she was denounced as being "ungrateful" following her freedom.
Previously, chair of the Foreign Affairs Committee and Conservative MP Tom Tugendhat said Ms Zaghari-Ratcliffe is "right to ask for answers" as he launched a select committee inquiry into the government's handling of her six-year Iran hostage ordeal.