UK political leaders have united to urge Sudan to lift the "barbaric" death sentence handed down to a Christian woman accused of abandoning Islam.
A court ruled that Meriam Ibrahim, who was raised by her Christian mother and married a Christian, was Muslim in line with her father - which she rejects.
David Cameron, Ed Miliband and Nick Clegg said the case appalled them.
A Sudanese government official later told the BBC there was no doubt the woman would be released.
Abdullahi al-Azreg - under-secretary at Sudan's Ministry of Foreign Affairs - said the country guarantees freedom of religion and the government was committed to protecting her.
The UK Foreign Office said it was "urgently seeking clarification" from Sudan that Ms Ibrahim was to be freed.
Officials had been urging the Sudanese government "to do all it can" to overturn the death sentence, a spokeswoman added.
Ms Ibrahim, who has appealed against her sentence, gave birth to a daughter in her cell on Wednesday.
David Cameron said her treatment had "no place in today's world", while Lib Dem leader Mr Clegg and Labour leader Mr Miliband both said her case was "abhorrent".
Meanwhile, former defence secretary Liam Fox said the UK should reconsider whether it was "acceptable" to give aid money to "states which allow treatment such as that handed out to Meriam Ibrahim".
But that suggestion was dismissed as "totally perverse" by Justine Greening the international development secretary.
"British aid to Sudan only goes on helping the very poorest Sudanese people via the UN and NGOs, and not a penny is given to the Sudanese government," she said.
Mr al-Azreg insisted international pressure had had no bearing on the decision to release Ms Ibrahim, which he said followed a "judicial process".
"I don't have any doubt that Meriam will be released and will not be executed, make no mistake about it," he said, adding that the "complicated" case had touched on tribal and social issues.
Ms Ibrahim's husband, Daniel Wani, who is a US citizen, told the BBC he was hopeful his wife's appeal would succeed.
He said he had seen his new daughter in prison on Wednesday, and that they were both doing well.
But he said he was most concerned about his 20-month-old son, who has been living with his mother in prison since February.
"His attitude has changed a lot," Mr Wani said.
"He used to be a happy boy. When I went there, he just looked at me. No smile."
Ms Ibrahim, 27, was brought up as an Orthodox Christian, but a Sudanese judge ruled earlier this month that she should be regarded as Muslim because it had been her father's faith.
She refused to renounce her Christianity and was sentenced to death by hanging for apostasy.
The court said she would be allowed to nurse her baby for two years before the sentence was carried out.
Her Christian marriage, in 2011, has been annulled and she has been sentenced to 100 lashes for adultery because the marriage is not considered valid under Islamic law.
Mr Cameron said: "Religious freedom is an absolute, fundamental human right."
"I urge the government of Sudan to overturn the sentence and immediately provide appropriate support and medical care for her and her children."
Deputy Prime Minister Mr Clegg said the sentence was a "flagrant breach of international human rights".
Mr Miliband said the incarceration of Ms Ibrahim was "utterly appalling and an abhorrent abuse of her human rights".
"Nobody should be persecuted because of the religion they practice or the person they fall in love with," he said.
Former Prime Minister Tony Blair described the case as a "brutal and sickening distortion of faith", the Times newspaper reported.
Human rights organisation Amnesty International has launched a petition calling for the Sudanese government to release Ms Ibrahim.
Sudan has a majority Muslim population and Islamic law has been in force there since the 1980s.