GETTY Theresa May and Emmanuel Macron

In a major boost to British negotiators leaked emails from the French president’s campaign team show how his chief officials believed securing a bilateral alliance with the UK is a top priority. On the other hand, a clutch of scathing missives are derisive about Brussels’ military integration plans, describing them as foundation-less and at the mercy of German whims. The leaks emails demonstrate the extent to which defence cooperation can be Britain’s trump card during the negotiations given our status as the continent’s number one military power.

But they will also raise fears that the UK Government has signed up to too many of the EU’s integrationist defence initiatives in recent months, potentially weakening that bargaining position. The trove of emails, which contain messages sent by a handful of Mr Macron’s senior campaign staff as well as many more peripheral figures, have been released this morning by WikiLeaks. Critics believe that the hacked data was provided to the whiste-blowing site by the Russian state, in the same way as the Hillary Clinton campaign emails published last Autumn, although just as then WikiLeaks denies this.

One of the emails, dated October 2 last year, contains a report written by Mr Macron’s industrial affairs advisor, Hervé Grandjean, for the French president’s chief speechwriter, Quentin Lafay. It outlines the future of defence relations between Britain and France after Brexit, detailing how the two countries currently cooperate and what the UK leaving the EU might mean. In it Mr Grandjean writes: “Brexit will necessarily have potentially contradictory effects on bilateral cooperation. Both governments have insisted on the preservation and strengthening of the bilateral partnership.” He says that intelligence sharing, such as in counter-terrorism operations, will be a key area of cooperation in future but then goes on to question the value of the EU’s military plans. The defence advisor writes: “In terms of multinational interventions and industrial cooperation, France is going to be caught between the temptation to seize Brexit to advance the CSDP [Common Security and Defence Policy - the EU’s military plans] and the desire to maintain a critical mass of exchanges with the British who - despite their present obvious withdrawal - remain the most important and the most active country in the field of defence.”

The British remain the most important and the most active country in the field of defence Macron advisor Herve Grandjean

Mr Lafay acknowledges the email and says he will keep other senior Macron advisors, including colleague Clement Beaune, in the loop so they can inform the candidate’s policy. In a second separate email, sent a week later, Mr Macron’s former defence advisor Francois Heisbourg shares an exchange with Mr Beaune about Brussels’ plans to integrate European militaries. He delivers a scathing assessment of the bloc’s proposals for a Permanent Structured Cooperation (PESCO) system, comparing it unfavourably to the incomplete eurozone. And Mr Heisbourg suggests that the German government, often seen as a key champion of military integration, is less keen on the idea if it involves handing more cash over to Brussels. He writes that the EU’s current defence plans are “overly ambitious” and have no proper foundations “a bit like a single currency that would like to live without either a central bank or an economic government”.

Emmanuel Macron's inauguration as French president, in pictures Sun, May 14, 2017 Emmanuel Macron is elected president of France, defeating Marine Le Pen, who threatened to take France out of the European Union. Play slideshow AFP/Getty Images 1 of 32 French President Emmanuel Macron poses with his wife Brigitte Trogneux at the Elysee presidential Palace