LONDON, England - Fernando Alonso decided to leave Ferrari more than a year ago.That's according to Flavio Briatore who has played a leading role in the Spanish driver's management throughout his career.After five years in red Alonso decided to return to McLaren for 2015 to lead the British team's new works Honda era but Briatore told Italy's La Gazzetta dello Sport that Alonso basically made his mind up to leave Ferrari in 2013.EMPTY PROMISES"It was a gentlemen's agreement with (Luca di) Montezemolo," Briatore said. "'If the (2014) car was not up to it, adios'. All it needed was a handshake. Fernando was tired of the usual refrain: 'You'll see, the next one will be a winning car'."Gazzetta also suggested that Alonso and Briatore had urged Ferrari to use its veto power to stop the move from the old V8 formula to turbo V6 engnes for 2014 and beyond. "The problem in 2013," Briatore explained, "was clearly the aerodynamics, as regards the engine we (Ferrari) were right there with the competition."So, there was this 'leap in the dark' taken with the engine. Alonso also felt the efforts made in the recruitment of technical staff was insufficient - that Ferrari should have been wooing the No.1, not the number 25!"Alonso's new home will be McLaren, where his 2007 tenure ended spectacularly badly. Briatore said: "Time heals everything."SPONSORSHIPS INVOLVEDRumours however suggest that talks between Alonso and Mercedes took place in 2013 but Briatore insists there was "never a serious negotiation". He also suggested Alonso was attracted by the resources being pledged to the McLaren project by Honda and denied that the double F1 champion demanded that his 2015 team mate be Jenson Button."It was an internal matter concerning sponsorships," Briatore said, "but we are happy because he (Button) is a good guy, smart, clever. He has already worked with Fernando in my team (Renault)."