The family's legal team are already working on the case and intend to insist that, because 18-month-old Charlotte's condition is constantly changing, no court can declare in advance what should happen if she stops breathing.
Lawyers made the announcement after Debbie and Darren Wyatt, of Westminster Place, Buckland, Portsmouth, suffered a setback yesterday at London's High Court.
Judge Justice Hedley confirmed his earlier decision that doctors at St Mary's Hospital do not have to resuscitate Charlotte – born premature with severe brain and lung problems – if she stops breathing again.
Immediately after the hearing, the Wyatts' solicitor, Richard Stein, said the fight would go on.
'There is another case before the Court of Appeal based on the same principle, and both cases could be heard together within three weeks,' said Mr Stein. 'If not, I don't think we will have any difficulty gaining a hearing within six to eight weeks.'