A British ISIS bride wants to come home from Syria. So the UK revoked her citizenship.

The British government revoked the citizenship of a teenager Tuesday who ran away to join ISIS — a decision her family’s lawyer says leaves her stateless.

Shamima Begum was 15 when she and two friends from her London school travelled to Syria to marry ISIS fighters in 2015.

Now 19, she has been the focus of renewed media attention after journalists found her earlier this month in a Syrian refugee camp containing hundreds of wives, widows and children of ISIS fighters. She told reporters that she wanted to return home to the UK.

Begum, who gave birth to her third child last weekend, was unrepentant, saying that while she disagreed with some of ISIS’s positions, she had no regrets about her actions.

She said she had been aware of the group’s atrocities before she travelled to join, but had been comfortable with them because “from what I heard, Islamically that is all allowed.”

She also described the 2017 Manchester Arena terror attack, at which 22 people were killed at an Ariana Grande concert, as “retaliation” for Western strikes on ISIS strongholds.

Her case has sparked fierce debate in Britain on how the country should treat its nationals who joined ISIS and are now, with the caliphate reduced to a sliver, seeking a return. The news that the Home Office had ordered her citizenship to be revoked was welcomed by those who claimed it was a necessary move to protect the country, and condemned by others who saw it as potentially illegal step that shirked Britain’s obligations.

British Home Secretary Sajid Javid has publicly taken a hard line against ISIS returnees, vowing on Friday: “If you have supported terrorist organizations abroad, I will not hesitate to prevent your return.”

It was revealed Tuesday that his department had made good on that pledge. A letter sent from the Home Office to Begum's mother, obtained by ITV News, said: “In light of the circumstances of your daughter … the order removing her British citizenship has subsequently been made.”

Her family's lawyer, Mohammed Tasnime Akunjee, said they were “disappointed” with the decision and are considering “all legal avenues” to challenge it, in line with her right to appeal.

He says the move has effectively made his client stateless, which is against British law.

The British Nationality Act of 1981 allows the government revoke somebody’s British citizenship if it would be "conducive to the public good" — only so long as that would not make the person stateless.

Government sources have indicated that Begum is eligible for Bangladeshi nationality through descent, making the move to revoke her British nationality valid, although Akunjee says Begum has never held a Bangladeshi passport nor visited the country.

Begum, who was alerted to the news by ITV Wednesday, said the move to strip her citizenship was “kind of heartbreaking” and “a bit unjust on me and my son.” The 19-year-old gave birth to two other children in Syria, both of whom died in infancy from malnutrition and illness.

The teenager, who is married to a Dutch ISIS militant who surrendered to Syrian fighters two weeks ago, said she might explore seeking Dutch citizenship through her husband. “If he gets sent back to prison in Holland I can just wait for him while he is in prison,” she said.

While the Home Office’s move was hailed by many, it has also faced criticism as a potentially illegal decision that sought to shirk the British government’s obligations to administer justice — and potentially attempt to rehabilitate — its own extremists.

“If the government is proposing to make Shamima Begum stateless it is not just a breach of international human rights law but is a failure to meet our security obligations to the international community,” said Labour’s Diane Abbott. “Potential citizenship rights elsewhere are entirely irrelevant.”

The decision faced criticism even from within the ruling Conservative party, with MP George Freeman labelling it “a mistake and a dangerous precedent.”

“She was born here, educated here and is our responsibility. We should defend our system and she should be brought back to face the UK courts,” he said.

Others have said the case highlights the need for an update of British laws to fit the current security climate — by overhauling treason laws to deal with people who join terror groups, for example.

Javid told MPs this week that more than 100 dual nationals had already been stripped of their British nationality for belonging to terror groups — including two members of the notorious ISIS execution cell dubbed “the Beatles.”

More than 900 Britons had travelled to Syria or Iraq to join the terror group’s so-called caliphate, he said. “Whatever role they took in the so-called caliphate, they all supported a terrorist organization and in doing so they have shown they hate our country and the values we stand for.”

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Javid added that the government would refuse to risk the lives of any British officials or military officials to help them.

Despite President Donald Trump’s call for governments to take back their citizens who joined ISIS, European countries have been reluctant to do so.

Begum’s case mirrors that of Hoda Muthana, a jihadi bride who left Alabama to join the terror group aged 19, and is now appealing through media interviews to be allowed to return home with her 18-month-old son.

Cover image: A screen grab taken from the ITV News interview with Shamima Begum.