21 races on 2016 F1 calendar, but regulations only allow for 20

The 2016 F1 calendar has been thrown into doubt after the FIA's published the F1 sporting regulations for next year.

Although 21 races have been listed on the provisional calendar, Article 5.4 of the 2016 Formula 1 Sporting Regulations states 'the maximum number of Events in the Championship is 20, the minimum is 8'.

The 19 races of 2015 will be bolstered next year by the return of the German GP and a new race around the streets of Baku in Azerbaijan dubbed the European GP.

The latest provisional schedule issued by the World Motorsport Council earlier in October sees the season start in Australia on March 20, concluding in Abu Dhabi on November 27.

The regulations say a final calendar will be published by the FIA before January 1, 2016.

The rules do make provision for in-season testing in 2016, stating that two, two day team tests can take place following an event at a European track.

Updated provisional 2016 F1 calendar

March 20: Australian GP

April 3: Bahrain GP

April 17: Chinese GP

May 1: Russian GP

May 15: Spanish GP

May 29: Monaco GP

June 12: Canadian GP

June 19: European GP (Azerbaijan)

July 3: Austrian GP

July 10: British GP

July 24: Hungarian GP

July 31: German GP

August 28: Belgian GP

September 4: Italian GP

September 18: Singapore GP

October 2: Malaysia GP

October 9: Japanese GP

October 23: United States GP

November 6: Mexican GP

November 13: Brazilian GP

November 27: Abu Dhabi GP

Don't miss Wednesday night's F1 Midweek Report for analysis of the Russian GP and all the latest talking points in the sport. GP2 team owner Trevor Carlin and F1 Racing magazine editor Anthony Rowlinson join Natalie Pinkham in the studio at 8.30pm on Sky Sports F1.