FIA change ruling on engine supply

The FIA has amended its regulations on power units to ensure manufacturers will not be permitted to supply older engines to another Formula One team.

There has been much talk about Red Bull's future in the sport with uncertainty over the team's source of power beyond this season, as relations with current engine supplier Renault are reportedly beyond repair.

Red Bull stressed that they would only continue in F1 if they were able to agree a deal for a supply of power units that would make them more competitive once again.

The team principal of Toro Rosso, regarded as Red Bull's junior team, Franz Tost stated they would be prepared to use a 2015 engine as they continue talks with Ferrari if it allows them to stay in F1.

But that would not be allowed under the new ruling, which was revealed on Wednesday.

"Only power units which are identical to the power unit that has been homologated by the FIA in accordance with Appendix 4 of these regulations may be used at an Event during the 2016-2020 Championship seasons," read a statement on the F1 website.

The change of ruling would allow such as Mercedes or Ferrari to use different software mapping or fuel products to teams they would supply engines to.

It was also stated that the new regulations could be changed "with the unanimous agreement of all competitors entered in the 2016 Championship, save for changes made by the FIA for safety reasons which may come into effect without notice or delay".

Manor-Marussia have been allowed to race this season with 2014 power units supplied by Ferrari.