Analysing the relationship between the executive and the courts is particularly interesting to an English lawyer when it takes place at a conference devoted to constitutional law. In the UK, we of course have no written constitution, and the term "unconstitutional" has no defined legal content. As a Canadian writer put it, for the American, anything unconstitutional is illegal, however it may seem: for the British, anything unconstitutional is wrong, however legal it may be.
Richard Clayton, The Executive and the Courts, 28 Penn St. Int'l L. Rev. 513 (2010).