For years we have heard threats from Formula One's teams about leaving the sport, buying the sport or joining a rival series. It has become something of a stuck record and now F1, and in particular, the sport's governing body the FIA, has a new threat to worry about. It has come right out of the blue and appears in an article in today's Express written by Pitpass' business editor Christian Sylt. In a nutshell, 17 race promoters, including Monaco, Monza, Silverstone and Spa, have all agreed to stop holding F1 races and run IndyCar instead if new smaller engines are introduced to F1 tomorrow. It is hard to believe but it is no idle threat.

The catalyst for this situation was the decision in December by the World Motor Sport Council (WMSC) to introduce to F1 from 2013 four cylinder 1.6 litre engines with a maximum of 12,000 rpm. This proposal met with huge resistance from most F1 teams as well as the sport's boss Bernie Ecclestone due to it being a 33% reduction in power from the current eight cylinder 2.4 litre engines which run at 18,000 rpm.

The change was heralded as a move to make F1 greener since the smaller engine would cut carbon emissions. However, the reduction of the rev limit would also affect the exhaust note and make the cars sound far less impressive than they currently do. It may not matter much to television viewers, but for spectators, who are the race promoters' bread and butter, it is of paramount importance.

On 3 June the WMSC approved the regulations containing the new engines which brought them one step closer to being used. The resistance to this led to the proposal being modified on Wednesday by the Formula 1 Commission, a decision-making forum for the teams and major stakeholders. The F1 Commission decided to delay the introduction of the engines by one year until 2014 and they were switched to V6 models instead of the previously proposed four cylinders. This is due to be written into the regulations tomorrow by a WMSC fax vote. However, one crucial change has been left untouched - that the new engines will run to 12,000 rpm. This has lit the touch-paper with the circuits and it is no surprise.

According to F1's trade guide Formula Money it costs the circuits £619m ($988m) to host F1 races and the only income they receive is from ticket sales. The broadcast fees and income from F1's trackside advertising and corporate hospitality all flow to F1's parent company Delta Topco, which is majority owned by private equity firm CVC. So the race promoters will carry all the losses if crowd numbers fall due to the cars' performance or engine volume going down.

Ron Walker, chairman of the Australian Grand Prix Corporation, represented the circuits at the Commission meeting and speaking to Sylt on Friday he described it as "a real showdown. It was the first showdown that the promoters have ever had with that commission and they understand exactly where we are." That's no exaggeration.

Walker says that "the proposal by the World Council for the first time galvanised all the promoters together, including Monaco, and they gave me their letters of authority and their proxies, to vote against the engine... 17 of the circuits gave me their proxies to tell them that. The only people that didn't allow me to vote for them was Korea and China."