Liberty Media's 2021 proposal has attracted ZERO manufacturers

Liberty Media's 2021 shake-up of Formula 1 appears to have taken another blow, after FIA president Jean Todt suggested that the regulation changes implemented in the new Concorde Agreement will not immediately attract a new manufacturer to the sport, as they are designed to do.

The likes of Porsche and Aston Martin have been credited with potential interest in joining F1 when "cheaper" and "simpler" power units as well as a budget cap are due to be drafted in.

However, it has recently been claimed that the regulations could end up being pushed back – Red Bull team principal Christian Horner estimated that an engine change wouldn't come into effect until 2023.

And Todt's latest claim suggests that Liberty's flagship proposal will fall somewhat flat – the Frenchman claiming that focus is in fact on ensuring that Mercedes, Ferrari, Renault and Honda do not leave.

"There was some demonstration of interest from one, who said to us we are not in a situation to commit for 2021 but what is very important for us is to know exactly what will be the regulations, because there could be a strong interest in the future," said Todt.

"My priority is to make sure that we keep them four.

"I always said it would be very unfair to the four engaged to say, 'OK, we want to attract a new one so let's change everything'.

"But what about them? What about all the investment they have been doing for years and we say, we change completely the regulations because we may have one or two coming?

"That is one of the reasons why it was not a revolution on the engine regulations.

"Now if we can secure those four for me that would be a great achievement."