Image copyright PA Image caption The prime minister said it was "absolutely terrible" to think of infants spending time behind bars

David Cameron has called for an urgent rethink of the way the prison system in England and Wales treats pregnant women and mothers with babies.

Ministry of Justice figures suggest 100 babies spent time living with their mothers in prisons last year.

The prime minister said it was "absolutely terrible" to think of infants spending time behind bars.

Labour said Mr Cameron had made promises on prisons before but they were still violent and overcrowded.

Mr Cameron, who is due to give a speech on prisons policy on Monday, said: "There are actually women in these prisons who were born in the same prison 20 years earlier, and then have ended up there later as criminals themselves.

"Think of the damage done to the life chances of these children."

'Break the cycle'

At present, when a woman gives birth while serving a custodial sentence, she is usually transferred to a prison's mother-and-baby unit (MBU) for an initial period.

MBU policy requires that these units should be available to accommodate babies up until the age of 18 months.

Mr Cameron said: "It's time to think seriously about whether this is the right approach.

"We've got to break this cycle."

The review will look at whether female offenders with babies could be dealt with by special problem-solving courts, housed in resettlement units or electronically tagged, rather than being locked up.

Downing Street said alternatives to custody would not be appropriate in every case and in some circumstances it could be in the best interests of the child for both mother and baby to be together in prison.

Image caption Ministry of Justice figures suggest 100 babies spent time living with their mothers in prisons in England and Wales last year

The government also announced that a major pilot of satellite-tracking technology would launch later this year.

The tagging system could be used to track the movement of non-violent offenders, potentially changing how prisoners are released on licence or the way community sentences are enforced.

'Head in the sand'

Labour's shadow justice secretary Lord Falconer said: "With an estimated 200,000 children affected by parental imprisonment, many of whom are more likely to have mental health problems and to be involved in offending, it is right that we urgently look at the way the criminal justice system treats pregnant women and mothers with children.

"It is also right that we should look at alternatives to custody for low-level offenders and, as Labour has long argued, we should also build on the success of the youth justice model to seek to divert more women away from the criminal justice system.

"But we have heard many of David Cameron's promises before and it is worrying that the government is still burying its head in the sand when it comes to the state our prisons are in.

"Violent, overcrowded prisons will never be able to rehabilitate offenders and ministers must urgently address the crisis in our prisons."

Juliet Lyon, director of the Prison Reform Trust, said: "There is huge sense in making sure that women pay back for what they have done in the community rather than suffer harsh separation from babies and toddlers in prison and the long-term damage that does."