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
The unlicensed events unfolded on Saturday night at Clapham Common and Tooting Bec Common.
A 37 year old man who was taken to hospital after getting into difficulty in a stretch of water near Maidenhead has died.
Jonty Bravery, who is mentally ill, has been jailed for 15 years after throwing a six year old boy from the Tate modern balcony.