The troubled Renault Formula One team suffered a setback this week when lead driver Russian Vitaly Petrov delivered a scathing appraisal of their on and off-track failings. Team boss Eric Boullier, however, has hit back at critics by claiming Renault were set to break through to a bright new era -- with a new identity following the deal to be re-branded Lotus. During an interview with Russia 2 television channel, Petrov blamed the team\'s lack of development and a series of mistakes with pit-stops and strategy for their decline in the second half of this season. \"We have lost positions in about 10 races or even more,\" Petrov said. \"Even without a fast car we could have gained good points, we could have finished with points if we had had a good strategy.\" Renault have scored only six points in eight races since the German Grand Prix in July, a spell that also saw experienced former lead driver German Nick Heidfeld ousted and replaced by Brazilian Bruno Senna. The team\'s slide has left them struggling to hang on to fifth place in the constructors\' standings with 72 points, 87 behind fourth placed Mercedes on 159 and only 15 ahead of sixth-placed Force India on 57. Renault\'s fall has left many paddock observers puzzled, if not stunned, as it is only five years since they completed a championship double with former ace, Spaniard Fernando Alonso, who took the drivers\' title in 2005 and 2006. Few of the team that helped carry Alonso to such glorious success remain after successive years of disappointment and upheaval including a change of ownership. Renault is now owned by the Genii Capital investment group led by Luxemburg-based Spaniard Gerard Lopez and has recently completed a deal enabling the team to be re-branded Lotus next season, an achievement that Frenchman Boullier believes will end their problems. \"This is massive for us for many reasons,\" he said. \"We now have a proper identity and we know who we are,\" he said. \"The Lotus project is much bigger. Something should be announced quite soon I hope and it is a nice way to secure our future with a new identity. It will change everything.\" Petrov, 27, who is in his second season with the team after becoming the first Russian driver to race in Formula One in 2010, finished one lap off the pace in 13th place for Renault in last weekend\'s Abu Dhabi Grand Prix. His mediocre, if not poor, performances in the second half of the year means he could be replaced next season as the team seek an all-new line-up to go with the Lotus re-branding. Frustrated Petrov\'s outburst was his first against the team and many have interpreted it as evidence of a rift that could be terminal. It may signal that Petrov has learned already that he is not included in Boullier\'s plans for 2012 and beyond. \"Unfortunately I cannot say anything bad about the team -- it says so in my contract,\" said Petrov. \"But many things have already been written about (this) in the media. People say the team criticised the drivers, but -- excuse me -- read my interviews. \"I haven\'t criticised the team despite what we have lost so many times (sic). How much have we missed at pit-stops? With strategy? \"I couldn\'t say in interviews that we lost it with the pit-stops, and I cannot talk about that now either, but I can\'t keep silent any more - it is over. I can\'t keep everything inside any more.\" After a season of confusion, Renault and Petrov will head to the final race in Brazil next weekend hoping to stop the rot before the start of a new, and for Petrov a possibly uncertain, era.