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".
More top news
Footage shows the moment a man allegedly attacked a shopkeeper at knife point.
Hertfordshire based eBay seller relists ad for the car that "ruined her life" after the auction website deleted it for swearing.
The accident happened on Clapham Road at lunchtime.