A single mother has lost the latest round in her legal challenge to stop life support treatment for her brain-damaged daughter being ended.

In a judgment on Friday, the Court of Appeal upheld an earlier High Court ruling that said 5-year-old Pippa Knight should be allowed to die.

Pippa suffers from acute necrotising encephalopathy and has been in hospital for the last two years. Doctors treating her at Evelina Children's Hospital in London said it was in her best interests to end life-support treatment and allow her to die, a decision High Court judge Mr Justice Poole agreed with in January. 

Her mother, Paula Parfitt, wants to be allowed to take her daughter home on a portable ventilator so that she can continue to be cared for by family.

In Friday's verdict, three judges in the appeals court, Lady Justice King, Lord Justice Baker and Lady Justice Elisabeth Laing upheld the decision of Mr Justice Poole.

Lord Justice Baker said in a written ruling: "I am entirely satisfied that the judge was entitled to conclude and declare that it was lawful and in Pippa's best interests that life-sustaining treatment be withdrawn for the reasons he gave in his judgment."

The other two appeal judges said they agreed.

John Deighan, Deputy Chief Executive of the Society for the Protection of Unborn Children, which has been assisting Ms Parfitt, said: "This is a desperately sad day and a decision which allows despair to triumph over hope. In Pippa's case, her right to life has been sacrificed through the judicial process.

"This courageous young girl has fought to live with every breath in her body for the last two years but the court has decided that fight has been in vain.

"Many will share our angst and deep concerns that we live in a society in which the value of a human life is treated with such disregard.

"Our thoughts are now with Paula who just days ago celebrated Mother's Day with optimism, going for a walk in the Spring sunshine with Pippa on a portable ventilator which could have been used to prolong her life at home." 

SPUC said it will seek legal advice before a decision is made about further legal action. 

Commenting on the case, the Catholic Auxiliary Bishop of Westminster, John Sherrington, said it was a "tragedy" and "profoundly sad".

"The Catholic Church teaches that every person has worth and dignity which is independent of their condition. Lack of awareness does not diminish worth," he said. 

"The ruling to allow medics to cease Pippa's treatment based on her quality of life or worth does not acknowledge or afford her the inherent human dignity with which she was born. The determination of continuing treatment must be in accord with the benefits and burdens which this or a different regime of treatment provides.

"We must uncompromisingly ensure that proper care is given where there is still life, despite serious illness or disability. We are reminded that such care must include the provision of nutrition and hydration, by whatever means, which is neither treatment nor medicine, unless this itself becomes overly burdensome."

He added, "The intentional ending of the life of a critically ill patient because of a judgement made of its quality is never in the patient's best interests. At the heart of humanity must be a call to show love and solidarity with the most vulnerable in society, and to defend the lives of our more fragile brothers and sisters who are unable to do so themselves."