Nazanin Zaghari-Ratcliffe pictured on flight home from Iran after six years in captivity

ITV News International Affairs Editor Rageh Omaar reports on the six-year battle to get the mother back to the UK and why it took so long

British-Iranian mother Nazanin Zaghari-Ratcliffe is on a flight home from Iran after spending six years in captivity there.

Ms Zaghari-Ratcliffe was seen boarding the plane in Tehran on Wednesday morning and Labour MP Tulip Siddiq confirmed that she has since touched down in Muscat.

From there, she will fly to the UK and finally reunite with her family.

Fellow British-Iranians Anousheh Ashoori and Morad Tahbaz who had been detained have also been freed, Foreign Secretary Liz Truss confirmed, but Mr Tahbaz is on "furlough" from prison and unable to leave Iran.

Ms Truss said the government would continue to work to seek the 66-year-old's release from Iran.

She said the key to their release was paying off a more than 40-year-old £400 million debt by Britain to Iran.

Oman's foreign minister, Badr Albusaidi, said Ms Zaghari-Ratcliffe and Mr Ashoori - who had been detained for five years - had arrived "safely" in Oman and shared an image of the pair being greeted by officials as they got off the plane.

"Sincere thanks for the hard work and good faith in Tehran and London that made this possible. Soon they will be with their loved ones at home," tweeted Mr Albusaidi.

"We hope this result will bring further progress in the dialogue between the parties."

Prime Minister Boris Johnson said it is "fantastic news" that Mrs Zaghari-Ratcliffe has been freed and paid tribute to her husband Richard Ratcliffe, as he described the result as "a great deal of UK diplomacy".

'We have known for years that her being held was linked to the fact that we owed Iran this £400m,' ITV News Political Editor Robert Peston reports

Mr Ratcliffe - who had previously gone on hunger strike outside the Iranian embassy in London to campaign for his wife's release - described the relief he and his family feel at the good news.

Speaking alongside their daughter, Gabriella, near their home in West Hampstead, he said his wife's return will mark "the beginning of a new life. A normal life."

The father said he hasn't yet been able to have a "euphoric chat" with his wife as she wasn't able to speak much, and that he doesn't think they will quite believe it until they see her land in the UK.

"Homecoming is a journey, not an arrival. I don't think it will just be today, there'll be a whole process," he told reporters, acknowledging there will be "bumps no doubt".

"Hopefully we'll look back in years to come and be a normal family. This will be a chapter in our lives but there will be many more chapters to come."

When asked what they will do together as a family when his wife arrives home, Mr Ratcliffe said: "The first thing she always wanted to do was have me make her a cup of tea."

He joked that she will probably want the house tidying when she's back too, and hopes the family can enjoy a few "quiet" days away.

The father said he was really grateful to all who had supported their fight and "kept us in the sunlight".

Ms Zaghari-Ratcliffe's brother Mohammed said when his family realised she was on a plane coming home "everyone was crying" because they knew ”this is over”.

"It was tough, we had loads of ups and downs... I can remember every moment, every minute of these six years, it was really really bad for the family," he told ITV News.

Nazanin Zaghari-Ratcliffe's brother Mohammed told ITV News that "everyone was crying" when it was confirmed that his sister was on her way home

He said he was "really happy and relieved" that he can finally "go to bed without any stress and worry about my sister’s case. It’s a good feeling."

He added that the first thing he will do is give his sister a "warm cuddle", adding: "I'm happy to hand over her daughter to her and put the responsibility back on her shoulders."

Earlier on Wednesday, Ms Siddiq tweeted a picture of Mrs Zaghari-Ratcliffe on the first leg of her journey, saying she is "now in the air flying away from 6 years of hell in Iran".

The Labour MP later tweeted an image of herself with Mr Ratcliffe and Gabriella in Parliament on their way to meet Mrs Zaghari-Ratcliffe when she gets off the plane.

Mr Ashoori, 68, a retired civil engineer, father and husband, was arrested in August 2017 while visiting his elderly mother in Tehran and was detained in Evin prison.

His family said they were "delighted" that he has been released and is returning home after five years.

They said in a statement: “1,672 days ago our family’s foundations were rocked when our father and husband was unjustly detained and taken away from us.

“Now, we can look forward to rebuilding those same foundations with our cornerstone back in place.”

Earlier on Tuesday, Ms Siddiq told ITV's Good Morning Britain that Mr Ratcliffe was "happier than I've heard him sound in six years".

Foreign Secretary Truss confirmed the UK has paid a £400 million debt owed to Iran in order to secure Mrs Zaghari-Ratcliffe's release.

She said it is being paid in a way which complies with UK and international sanctions, with the funds that have been released being restricted to humanitarian purposes only.

Rageh Omaar explains why Britain did not pay the debt to Iran earlier:

The UK had owed Iran the hundreds of millions since the 1970s after Iran paid for 1,500 Chieftain tanks, an order that was never fulfilled after the shah was deposed and replaced by a revolutionary regime.

Defence Secretary Ben Wallace, explaining the debt and its clearance, said, in a written Commons statement: "On Thursday, March 10, 2022 I authorised the release of £393.8 million to discharge the debt owed by the Ministry of Defence-owned company, International Military Services Limited (IMS).

"The debt resulted from contracts which were signed between IMS Ltd and the pre-revolution Iranian government. Following the Iranian revolution, the contracts were not fulfilled, despite pre-payments made by Iran to the UK."

Speaking to reporters in the Saudi capital Riyadh, the prime minister said he was "thrilled" all three British-Iranians had been freed.

Asked about comments he made as foreign secretary which were blamed for exacerbating Mrs Zaghari-Ratcliffe's plight, the prime minister said: "We must always realise that, sadly, the regime in Tehran is capable of holding people in this way.

"I think that people do need to recognise that. I am glad that after a great deal of UK diplomacy we have been able to get her out, get her back to her family.

"I am absolutely thrilled for Nazanin, for Richard and for Gabriella."

Ms Zaghari-Ratcliffe was arrested in April 2016 by the Iranian Revolutionary Guard at Imam Khomeini airport following a holiday visit to Iran to see family, and was sentenced to five years in prison and after being found guilty of "plotting to topple the Iranian government", something Ms Zaghari-Ratcliffe has always denied.

As her sentence was due to end she was sentenced to another year in jail in April 2021.

Her lawyer said she received the second jail sentence on a charge of spreading “propaganda against the system” for participating in a protest in front of the Iranian Embassy in London in 2009.

A timeline of events from Mrs Zaghari-Ratcliffe's arrest to her release:

A glimmer of optimism for the 43-year-old came on Tuesday when Ms Siddiq said her British passport had been returned and she was staying at her family home in Tehran.