The future of the German Grand Prix appears to be hanging in the balance after Bernie Ecclestone revealed on Monday that he had ended negotiations with the Nurburgring over the 2013 event.
The Nurburgring was supposed to host this year's event as part of an alternation plan agreed with Hockenheim, but financial problems at the venue meant there was no guarantee it could fund the race.
Following weeks of talks to try to agree terms, Ecclestone has now indicated that a deal does not look like happening.
Speaking to German publication Spiegel, Ecclestone said: "After due consideration of their proposal we believe it is regrettably not financially acceptable, so we have terminated our negotiations."
The German GP's fate may now rest on Ecclestone sorting out a deal with Hockenheim, which hosted last year's race.
Should that plan not come off, then the Formula 1 calendar could be reduced to just 18 races - with plans for a 20th event having not reached fruition.
Turkey, Austria and Portugal were all linked with that vacant slot - which has been pencilled in for July 21 - but there has been no indication of a venue getting the green light.
If Germany does not take place, then it means there will be just one race - the Hungarian GP on July 28 - between the British GP on June 30 and the Belgian GP on August 25.
2013 Formula 1 calendar
17/03 AUS Grand Prix of Australia
24/03 MYS Grand Prix of Malaysia
14/04 CHN Grand Prix of China
21/04 BHR Grand Prix of Bahrain
12/05 ESP Grand Prix of Spain (Barcelona)
26/05 MCO Grand Prix of Monaco
09/06 CAN Grand Prix of Canada
30/06 GBR Grand Prix of Great Britain
07/07 DEU Grand Prix of Germany
28/07 HUN Grand Prix of Hungary
25/08 BEL Grand Prix of Belgium
08/09 ITA Grand Prix of Italy
22/09 SGP Grand Prix of Singapore
06/10 KOR Grand Prix of Korea
13/10 JPN Grand Prix of Japan
27/10 IND Grand Prix of India
03/11 UAE Grand Prix of Abu Dhabi
17/11 USA Grand Prix of USA (Austin)
24/11 BRA Grand Prix of Brazil