The politics of espionage returned to haunt Formula One in dramatic fashion yesterday as McLaren Mercedes went on the offensive against Renault. In a concerted attack, McLaren sought to underline that the French team’s possession of McLaren technical secrets is as bad or even worse than McLaren’s possession of Ferrari secrets.

A leaked briefing memo from McLaren on the so-called “Renault-gate” affair seen by The Times claims that Renault had more than 780 individual drawings, allegedly stolen from McLaren, on their Formula One computers that amounted to “the entire technical blueprint of the 2006 and 2007 McLaren F1 cars”.

The memo also names what it calls the “Renault seven”, a group of seven senior figures in the Renault design and technical team who McLaren say discussed the McLaren technical information. Among them is the Renault chief designer, the head of research and development, the head of mechanical design, the head of transmission design and the head of vehicle performance.

The leak from McLaren was being seen as an attempt by the Woking-based team to dispel the impression within the sport that the illegal transfer of technical information from McLaren to Renault is of an altogether lesser order of importance than McLaren’s possession of Ferrari secrets.

McLaren’s transgressions resulted in them being handed a £50 million fine by the FIA, the sport’s governing body, being thrown out of this year’s constructors’ championship and having their 2008 car subject to long-term scrutiny. Should the same penalties be applied to Renault, many believe that the team would quit Formula One.

The “Renault-gate” affair came to light in September this year when it emerged that Phil Mackereth, the former McLaren engineer who joined Renault in March 2006, had taken with him several old-style floppy disks containing McLaren technical drawings.

Renault have played down the importance of the drawings, claiming that they covered only four “basic systems”, at least one of which was obsolete. They claim that none of the information was used on their cars and that the information was immediately cleansed from the team’s computer once it was discovered.

McLaren paint a very different picture. The leaked memo, which quotes from McLaren’s submission to the FIA’s World Motor Sport Council (WMSC) that is due to hear the case in Monaco on December 6, says that at the time Mackereth left McLaren, 33 files of technical information were copied on to 11 floppy disks. These were then loaded on to Renault’s computer system in September 2006.

McLaren say that the 33 files, which offered a complete technical picture of McLaren’s cars in 2006 and 2007, were uploaded on to 11 Renault computers and were discussed by up to 18 Renault personnel.

In their submission to the FIA, McLaren’s solicitors, Baker & McKenzie, say: “It is clear that McLaren’s confidential design information was knowingly, deliberately and widely disseminated and discussed within the Renault F1 design and engineering team, thereby providing them [Renault] with a clear benefit and unfair advantage.”

The memo also notes that Baker & McKenzie have complained in writing to Renault’s solicitors about what McLaren claim is a “cavalier attitude” on the part of senior Renault personnel during the investigation into the affair and that other responses have been “incomplete”, “misleading” or “incorrect”. The memo concludes with an attack on Mackereth’s suggestion that he had kept some confidential McLaren technical information for “sentimental reasons”. In their submission to the WMSC, Baker & McKenzie describe this as an “absurd” explanation for his actions.

The leak of the memo from McLaren and its timing is as significant as what it contains. The Woking-based team have resorted to radical measures to pile on the pressure, not just on Renault but on the FIA in what looks like a fairly crude attempt to try to prevent the WMSC brushing this affair under the carpet.

However, only time will tell whether this could prove counter-productive. Max Mosley, the president of the FIA who has never seen eye-to-eye with Ron Dennis, the McLaren team principal, may take a dim view of McLaren’s decision to leak information from their confidential submission to the WMSC. There are also other powerful voices in the sport who do not buy McLaren’s version of this affair.

Rival teams drawing their own conclusions

- In March 2006 - about the time Phil Mackereth, the engineer, left McLaren Mercedes to join Renault – 33 files of confidential technical information belonging to McLaren were copied on to 11 floppy disks, which were loaded on to Renault’s Formula One computer system in September 2006

- These 33 files contain more than 780 individual drawings outlining the entire technical blueprint of the 2006 and 2007 McLaren cars

- The files were uploaded on to 11 Renault computers and were discussed by up to 18 Renault Formula One personnel – including “the Renault seven”, a group of senior engineering chiefs and heads of department within the team

- McLaren claim that Renault personnel are not taking the case seriously, accusing them of adopting a “cavalier attitude” to the investigation of the affair and not providing accurate information in written responses

- McLaren allege that Mackereth has made “inconsistent” statements to solicitors concerning the extent of the penetration of McLaren technical information within Renault