After the UK joined the Common Market on 1 January 1973 one of the first cases that considered the impact of EC law was P. Bulmer Ltd. and Another v J. Bollinger S.A.  Ch. 401.
In that case two English companies which had manufactured beverages described over many years as “champagne cider” and “champagne perry” began an action against two representative French champagne houses, asking for declarations that they were entitled to use those expressions in relation to their products.
Lord Denning famously said that “when we come to matters with a European element, the Treaty is like an incoming tide. It flows into the estuaries and up the rivers. It cannot be held back, Parliament has decreed that the Treaty is henceforward to be part of our law”.
With Brexit though comes the task of trying to turn back that tide, which has flowed into the estuaries and rivers of our law for 43 years. In many areas of law this is a vast task and one likely to take many years and cost hundreds of millions of pounds. In environmental law the task is especially daunting given the extent to which our environmental law is of EU origin.
Have these EU laws intermixed with our laws to such an extent that they can never truly be separated (this puts me in mind of the Roman Law dealing with the mixture of liquids, Confusio, see e.g. Indian Oil Corporation Ltd. v Greenstone Shipping S.A. (Panama)  Q.B. 345 …)?
Writing in the European Advocate (Spring 2016) Laws LJ noted just some of the many legal principles we have taken from the EU including “Legitimate expectations, proportionality, legal certainty, aspects of the law of discrimination … “ and suggested that even if Brexit happened “ … there is every reason to suppose that the common law will nevertheless retain the best of our legal imports” albeit they may have to be qualified and made “our own”. But much will surely be lost…
Still trying to keep with Lord Denning’s water simile the outcome of the referendum appears to me more like a decision to chuck the baby out with the bathwater…