My reading was that they would look to change the primary legislation if the appeal route was not an option... from The Independent quoting a 'spokesman':

"Experience in south east London certainly suggests that it can be necessary for changes to be made at more than one Trust in order to find a sustainable service model. That's why we are appealing the decision, and considering our further options carefully. It is certainly the case that one way to put the matter beyond doubt would be to amend the primary legislation governing the administration process."