Ad giant WPP has made its starkest warning yet that it may follow rival Publicis and turn its back on Cannes Lions. Leaked emails revealed a decision to walk away from the event rests with talks between senior WPP executives and Cannes Lions parent company Ascential early next month.

WPP also spelled out that its agencies must withdraw all involvement from European awards show, Eurobest, also run by Ascential and which takes place during November in London.

The internal email chain, obtained by AdWeek, lay bare WPP’s contempt for Eurobest and reveals a “final decision” on Cannes rests on discussions with Ascential chief executive Duncan Painter. It is unclear what concessions Cannes Lions needs to make to ensure the company’s continued participation although a more streamlined show is certainly among WPP’s demands. The talks will bring to a head Martin Sorrell’s long-held dissatisfaction with Cannes. The WPP boss has argued it has become too unwieldy and lost its creative focus.

The leaked email, penned by WPP worldwide creative director John O’Keefe and reportedly sent to senior executves last Friday, reads: “Final decisions on WPP and Cannes will await the result of a meeting Martin and I have with Duncan Painter in a couple of weeks time.”

On a more concilatory note, it adds: “But already we are seeing moves in the right direction: categories are being reduced by 120, there will be a refocusing on creativity, and there is talk of cutting the overall length of the festival.” The email belittles Eurobest as an “expensive distraction” and witheringly describes it as “the very poor relation to Cannes”. O’Keefe added: “It delivers no real credibility to us, nor does it much impress our clients.” Yet it also emerged that 117 entries had been submitted by WPP agencies to Eurobest, along with the offer of keynote speakers and jurors.

According to the AdWeek report, Sorrell wrote in the email chain: “Please cancel all entrees [sic] and attendees asap.” Terry Savage, the chairman of Cannes Lions, declined to comment when contacted by Mumbrella, saying he was unaware of the email. He also refused to comment when pressed on how important WPP’s involvement was to the festival.

Sorrell has previously spoken of the firm’s uneasy relationship with Cannes and questioned whether the festival truly reflects the creative qualities of the industry.

“The importance of recognising the outstanding creativity of our people and the work they do for clients is not in doubt,” Sorrell has said. “The question is whether the festival does that in the most effective way, and we look forward to playing our part in finding the best solution.”

In a previous interview Sorrell also directly raised the prospect of withdrawing describing it as a “very big exercise – a very expensive exercise”. Its troubled relationship with Cannes, coupled with a desire to cut costs, already led to WPP halving the group’s participation at this year’s festival from the 350 staff members who attended last year.

Back in 2016, Sorrell also threatened to pull WPP out of the festival, citing growing costs and problems with the event’s size. Should WPP’s demands not be met and it finally walks away from Cannes it would be a devastating blow for organisers.

It has been plagued with controversy in recent years over scam entries while next year’s event has already been weakened by the absence of Publicis.

After this year’s Cannes, at which WPP was named the world’s most creative parent company for the seventh successive year, O’Keefe said the 2018 gathering would be “poorer for their (Publicis’s) absence”. Cannes told AdWeek: “WPP is a valued Cannes Lions partner, and as with all our stakeholders we are discussing how we can deliver the best possible Festival experience that suits their requirements.

“These discussions are wide-ranging and cover many aspects of the event. We look forward to unveiling plans for the 2018 edition of Cannes Lions in November.”

Those plans will not include Publicis and whether WPP is part of them remains to be seen.