A Department of Health spokesperson said:
The Royal Brompton hospital has said it tried to avoid taking expensive legal action to keep open its children's heart unit. In a statement, the hospital's trust said it had been left with no choice:
"When serious assaults are made on patient care, when groundbreaking research teams who may be on the cusp of a significant breakthrough in cystic fibrosis tell us their research will not be possible under the proposals put forward, drastic measures are called for.
"We had to fight to protect the needs of patients - now and in the future. What better cause is there than the health of vulnerable children?"
The Children's Heart Federation charity has said it is "horrified" by the bill run up by the Royal Brompton Hospital, in its courtroom battle with another NHS body.
The hospital had challenged a consultation by the Joint Committee of Primary Care Trusts, which had proposed closing the children's heart unit at the Royal Brompton.
The charity has urged other hospitals not "to waste this level of money on further legal action".
Campaigners fighting to save a children's heart surgery unit have been left disappointed after the Court of Appeal ruled that consultations which proposed its closure were lawful.
Bosses at the Royal Brompton in Chelsea now fear that, if the current plans are approved, the future of the entire hospital could be under threat.
But those involved in the planning say no final decision has yet been made.
Liz Wickham has sent this report.
Although the Royal Brompton Hospital lost its case in the High Court today, a final decision on the future of its children's heart unit is yet to be made.
Proposals outlined by the NHS would see the number of children's heart units in London cut from three to two.
That would see the Royal Brompton's unit closed - leaving units at only Great Ormond Street and the Evelina Children's Hospital at Guy's & St Thomas' NHS Trust.
But the final decision will not be made until later this year.
Sir Roger Boyle, former national director for heart disease and stroke, said:
The Court of Appeal earlier decided that consultations - which led to proposals to close the children's heart unit at the Royal Brompton Hospital - were lawful.
The Royal Brompton Hospital has lost its Appeal Court challenge over consultations that led to a proposal to close its children's heart surgery unit.
Here are some extracts from a statement released by the Royal Brompton & Harefield NHS Foundation Trust following the judgement:
The Court of Appeal has ruled that consultations, leading to a proposal to close the children's heart surgery unit at the Royal Brompton Hospital, were lawful.