“This tragic situation is largely the consequence of the signing of several bilateral treaties and arrangements between France and the UK,” said the commission in a statement on the topic last year.
The commission added that “tangle of treaties”, which are largely in contradiction of EU law “leads to France becoming the police arm of British migration policy.”
Could France actually scrap the deal if it wanted?
The last article of the treaty of Touquet grants the two signatory powers the option of ending the treaty “at any time”, simply by informing the other party in writing, via diplomatic channels. There would however be a two-year delay before the change came into effect.
France also has powers to make changes to the treaty by a “simple exchange of notes” as well as taking the more drastic measure of employing its right to “take all necessary measures to safeguard its sovereignty and security”.
If President François Hollande's under-pressure government had chosen to change the deal, it would have been a hugely controversial move, according to professor Pierre-Yves Monjal, a public law specialist from the University of Tours in France.
“Parliament could be consulted but it is not mandatory. It would simply be enough if France announced to the UK that it was no longer willing to apply Le Touquet treaty,” he recently told L'Express magazine.
That move would almost certainly provoke a diplomatic crisis as well as a legal wrangle as London would likely challenge the decision at a national and European level.
The question of money would also play a part. In 2014 London agreed to hand over an extra €15 million over three years to help deal with the crisis in Calais.
If the French ever told the UK to move back its borders, there would still be an urgent security crisis in Calais, except the British would likely withdraw their financial help.
And the fear in France is that even more migrants would head to Calais if they thought it would be easier to get to Britain.