Charlotte's first visit home without medical staff was on Christmas Day

Darren and Debbie Wyatt told a BBC Radio Four documentary, to be broadcast on Thursday, that there were concerns they could not cope with her care.

From Friday, they will only be allowed to take the brain-damaged two-year-old home for four hours, twice a week.

A Portsmouth social services spokesman said the family was being assessed.

Charlotte has so far spent her life at St Mary's Hospital in Portsmouth after being born prematurely with severe brain and lung damage.

Her parents have fought a series of court battles with Portsmouth NHS Trust over the question of whether Charlotte should be given artificial ventilation if her condition worsens.

In October, on Charlotte's second birthday, the High Court lifted a court order that ruled doctors need not give Charlotte artificial ventilation in a life-threatening situation.

They say we can't cope but I know we can Darren Wyatt

Doctors still have the right to make a final decision but must now consult with Charlotte's parents and take into account their wishes before making a decision.

The Wyatts now claim social workers are questioning the quality of care they are giving their other three children and asking if they are able to look after Charlotte as well.

They say they are losing hope that Charlotte will ever come home to their two bedroom council flat.

Mr Wyatt said: "They haven't re-housed us to a place big enough to take Charlotte and all her medical equipment and now they're saying we can't have her anyway.

'Ability to cope'

"They're making little excuses like the flat is untidy, or there was a dirty nappy on the floor.

"They say we can't cope but I know we can."

Debbie Wyatt said she was suffering from post-natal depression after the birth of her fourth child before Christmas: "I don't feel like doing anything - some days I just want to stay in bed but I have to keep going for my other kids.

"I know they're well looked after - if they weren't social services would have taken them off us ages ago."

A spokesman for Portsmouth Social Services said of the ongoing assessment: "This involves looking at their needs and also their wider ability to cope.

"At this point we are not in a position to give more details about the position they are in."

The city council has previously said it was working to find the Wyatts a bigger home.