Siamese twin Jodie was last night battling for survival after the mammoth 20-hour separation operation which ended in the death of her weaker sister Mary.

The next 48 hours are vital for Jodie, currently in a critical but stable condition in the intensive care unit at St Mary's Hospital, Manchester.

She will be monitored closely as she fights to recover from the operation which saved her but was a death sentence for her twin.

Mary had been sapping the life from Jodie, whose heart and lungs had been keeping both of them alive.

Professor Lewis Spitz, consultant paediatric surgeon at London's Great Ormond Street Hospital for Children, said the little girl would need ''minute by minute'' monitoring for the next two days and possibly the coming weeks.

Prof Spitz, who has separated five sets of Siamese twins, said: ''These babies are extremely critical after surgery and they have to be carefully monitored."

The operation to save Jodie by separating her from Mary, who was said to be ''draining her lifeblood'' began just before 9am on Monday.

A team of 20 surgeons and medics, including two neurosurgeons, two orthopaedic surgeons and two general surgeons, were drafted in for the complex operation.

The parents of the twins, who cannot be named for legal reasons, had opposed the operation on religious grounds. They said a tearful goodbye to Mary, knowing she would die on the operating table.

Throughout the operation, regular progress reports were sent to them as they waited in a private room near the hospital bedroom that has been their home since the birth of the twins in August.

They are strict Roman Catholics from the Maltese island of Gozo and had believed the girls' fate should be left to God.

As they prayed for their twins, a handful of protesters gathered outside the hospital for a candle-lit vigil.

Surgeons worked through the night to separate Jodie and Mary, who were born with fused spines, joined at the abdomen and with their arms and legs at right angles to their upper bodies.

At 5am, 20 hours after it began, the operation was over and Jodie was transferred to intensive care