Next year's World Rally Championship schedule will be cast in stone after this weekend, when Rally Bulgaria – the sole FIA candidate rally for 2010 - runs.

The event is included in next year's calendar as a full round of the WRC, but that status is dependant on the FIA observer's report from this weekend's rally. Should this event not fulfill the necessary requirements, both Argentina and Italy are standing by as reserve events, ready to slot into the 13-round schedule for next season.

A source within the FIA said: "From what we have seen so far, Rally Bulgaria is a capable event. Obviously, it has a history in the FIA European Rally Championship - and it is a round of that series again this year. We have to wait and see how the event goes and we can't possibly prejudge that.

"What we do know, however, is that the credible and acceptable level of rallies at the WRC is being raised all of the time. We have a promoter in the WRC, which will only accept the best events. And with Argentina and Italy listed as reserves, Bulgaria has to put on a good show this week."

The event gets underway with a ceremonial start this evening, before running six stages tomorrow (Saturday) and six on Sunday. Based in the ski resort of Borovets, 60km away from the capital Sofia, the all-asphalt rally will include a total distance of 747km, 268km of which is competitive.

Former European champion Giandomenico Basso starts among the favourites in his Abarth Grande Punto, with top Polish driver Michal Solowow (Peugeot) also in the running for victory on what could be the most important event in Bulgarian rally history.