Lenaerts told Dutch radio program 'De Kennis van Nu':
"I would find it very regrettable for the EU that it would lose [the UK's] input… if it ever comes to a Brexit."
The remarks are in contrast to the UK Prime Minister Theresa May's contention that "Brexit means Brexit", meaning that the In-Out referendum on Britain's membership of the EU should result in the UK no longer being bound by the rules of Brussels.
Lenaerts said that the UK had never really been a great fan of the EU project, having opted out of some of the major pillars of the union.
"I have an enormous amount of sympathy and admiration for the UK and for Anglo-Saxon culture in general. It is a country with an enormous tradition when it comes to global trade, as well as maritime and military affairs. Furthermore, the influence of its unique common law system would diminish significantly at EU level. Only Ireland, Malta and Cyprus would still provide this kind of legal and judicial input to the Union.
"I am not stressing this out of disappointment or political activism. It is merely an objective fact. Grab the Handbook of EU law. Inside you will find dozens of pages with regards to the special status of the UK concerning the euro, the Schengen Area, or the Area of freedom, security and justice. The UK has never participated in any of these projects," he said.
The comments from such a senior EU lawyer, suggesting Brexit may not even happen, echo those of lawyers in the UK who have cast doubt on even the legality of the referendum outcome.
More than a thousand British lawyers wrote to — then — Prime Minister David Cameron pointing out that the result was merely advisory and not binding on parliament. They wrote:
"The European Referendum Act does not make it legally binding. We believe that in order to trigger Article 50, there must first be primary legislation. It is of the utmost importance that the legislative process is informed by an objective understanding as to the benefits, costs and risks of triggering Article 50 [of the Treaty of Lisbon, beginning the exit process]."
Meanwhile, lawyers Mishcon de Reya have launched a legal challenge to the referendum, saying the prime minister cannot invoke Article 50 without the consent of parliament, which does not have to abide by the result of the referendum (although going against the outcome will be political dynamite).
Kasra Nouroozi, a partner at Mishcon de Reya said:
"The result of the Referendum is not in doubt, but we need a process that follows UK law to enact it. The outcome of the Referendum itself is not legally binding and for the current or future Prime Minister to invoke Article 50 without the approval of Parliament is unlawful."