Shadow Foreign secretary Emily Thornberry condemned Mr Johnson for days of "obfuscation and bluster" where he failed to clarify his comments, as she urged him to state "simply and unequivocally" that he got it wrong.
She told the Foreign Secretary his "pride matters not one ounce compared to Nazanin's freedom".
The foreign secretary told MPs: "Of course I apologise for the distress, for the suffering, that has been caused by the impression that I gave that I believed that she was there in a professional capacity".
"She was there on holiday".
"I reject any suggestion that she was there in a professional capacity", he said.
Allies of Mr Johnson have reportedly said he was given an incorrect briefing by Foreign Office officials ahead of a committee hearing at which the comments were made.
Sierra Nevada Dream Chaser Conducts Critical Flight Test
Both SpaceX and Orbital ATK developed wingless cargo capsules that launch to the station on top of the companies' rockets. The company is under contract from NASA to fly its Dream Chaser spaceplane to the International Space Station by 2020.
More Sunshine, Warmer Monday
Across our region, clouds will give way to sunshine today, which will boost afternoon temperatures well up through the 50s. More sunshine moves in this week with afternoon temperatures mainly in the 50s aside from Thursday when we could reach 60°.
Ratcliffe told the BBC he hoped he could travel to Iran with Johnson to meet his wife.
But Mr Ratcliffe did reveal his anger with the Government's handling of his wife's case, adding: "Don't get me wrong, I've not always been happy with the Government, the Government knows that behind closed doors, the Government knows that on the media and so on. But at the same time I'm not trying to push for anyone to lose their job, I'm just trying to bring Nazanin home".
Mrs Zaghari-Ratcliffe's family has also stepped up the pressure in recent days as the mother-of-one's plight hit the national airwaves.
"He's certainly the right person now to go and compensate for the enormous harm he has done". Ms Zaghari-Ratcliffe was employed by the Thomson Reuters Foundation when she was arrested by Iran's Revolutionary Guard last April while visiting her parents with her two year-old daughter, Gabriella.
Conservative MP Micheal Gove has come under fire for claiming he did not know what British-Iranian citizen Nazanin Zaghari-Ratcliffe was doing in Iran when she was arrested in 2016.
The Herald recently reported that Nazanin, who is already serving a five-year jail term, is now facing fresh charges and could face an additional 16 years of imprisonment if convicted.
It comes as Downing Street said it was considering offering diplomatic protection to the mother-of-one, which would make the case a legal dispute between Iran and the United Kingdom, rather than a consular issue.
Michael Gove, Britain's Secretary of State for Environment, Food and Rural Affairs, arrives in Downing Street for a cabinet meeting in London, October 17, 2017.
Samsung CONFIRMS Galaxy A5 2018 Via Support Page
It is speculated that this particular model of the A series will bag an improved camera, in comparison to its predecessors. Apart from the FCC certification, the South Korean website also authenticated the arrival of the A5.
Former Irish global Liam Miller is battling cancer
The Ireland midfielder David Meyler said: "Thoughts go out to him and his family, from the whole team". Miller started his professional career with Celtic before moving to United in the summer of 2004.
Final Fantasy XV's Noctis coming to Tekken 7
All in all, it seems like the guy has plenty of tools at his disposal to make him one of the most risky characters on the roster. The announcement comes after yesterdays Tekken 7 World Finals and no other announcement of when he will be available.
Sweden shatter Italy's World Cup dream
The big news from the first leg is that Marco Verratti will miss the second contest after picking up a yellow card in Sweden. Immbobile beat Olsen with another but Andreas Granqvist got back for a decisive goal-line clearance.
Carbon emissions on track to rise this year
Global CO2 emissions from all human activities are set to reach 41 billion tonnes (41 Gt CO2) by the end of 2017. Data from the Department of Environment and Energy shows Australia's emissions have been increasing since 2013.