David Cameron has spoken out against the death sentence handed to Sudanese Christian woman Meriam Yehya Ibrahim for apostasy.

The 27-year-old was heavily pregnant at the time of the sentencing and gave birth to a baby girl last week behind bars.  Also detained with her is her 20-month old son. 

Although she was raised a Christian, her father - who walked out on the family when she was six years old - was a Muslim and for this reason, the Sudanese authorities consider Ibrahim to also be a Muslim. 

Her marriage to a Christian man was deemed invalid by the authorities and she therefore received the additional sentence of 100 lashes for adultery.   

Ibrahim considers herself a Christian and her death sentence was upheld by the court in Khartoum after she refused to recant her faith. 

She is allowed to nurse her baby up to two years, after which the authorities have determined she will be hanged for apostasy. 

Her husband Daniel Wani has been to see Ibrahim in prison and says both mother and daughter are doing well.

According to the BBC, Mr Cameron said he was "appalled" by the sentence and that it had "no place in today's world".

"Religious freedom is an absolute, fundamental human right," he said.

"I urge the government of Sudan to overturn the sentence and immediately provide appropriate support and medical care for her and her children."

Mr Cameron said the UK would continue to press Sudan "to act" as other political leaders spoke out against the sentence.

Deputy Prime Minister Nick Clegg said it was a "flagrant breach of international human rights" and the freedom to practise one's religion, while Labour leader Ed Miliband said "nobody should be persecuted because of the religion they practise or the person they fall in love with".

"I cannot imagine the suffering - both physical and emotional - that Meriam, her husband and their two young children must be going through," he said.