Christian Horner has urged the FIA to re-use the threat of introducing an independent F1 engine after the Red Bull team principal said an agreement over cost-saving rules has yet to be reached.
The sport's ruling body first pushed ahead with plans to have a budget power unit last October following failed attempts to implement cost-capping measures, as highlighted by Ferrari's use of its historic veto against such proposals.
One month later, the FIA launched "a consultation among the engine manufacturers in order to potentially identify for 2017, 2018, and 2019 seasons an exclusive alternative engine manufacturer".
In January 2016, F1 constructors eventually agreed upon solutions that would slash the price of their customer engines to around €12m (£8,6m), essentially rendering the concept of the independent engine moot. In exchange, the 1.6-litre V6 turbocharged power units are set to stay until at least 2020.
However, with the April 30 deadline to finalise next year's rulebook looming ever closer, Horner claims that necessary conditions have not been satisfied yet.
"[FIA president] Jean Todt set a criteria of four deliverables that [Mercedes motorsport boss] Toto Wolff, representing the engine manufacturers was charged with going off to achieve. And the four things were: a reduction in price to €12 million from next year, and the availability of those engines of supply, power convergence to within plus or minus 2% and to address the noise.
"All four to date haven't been met. So I think it's going to be an interesting discussion at the next strategy and Formula One commission meetings as to what the next steps of the FIA and the promoter will be to that.
"I think they need to decide what they want because they made it clear previously that the independent engine was tabled, it was removed from the table on the basis of these things being offered. If they’re now not available – if prices aren’t going to come down, convergence isn’t going to happen, supply isn’t going to be restricted – then the criteria hasn’t been fulfilled."
After winning four consecutive championship doubles with engine partner Renault from 2010-13, Red Bull has been trailing the likes of Mercedes and Ferrari in terms of horsepower in the latest turbo era. With its current deal with the French constructor set to expire at the end of 2016, Horner adds that the FIA is right to pursue the independent engine avenue.
"How else are you going to deal with price affordability and availability? Convergence? It’s still a major, major issue. The racing is good at the moment but we’ve still got this underlying issue that needs to be addressed. It’s going to be interesting. It’s not something that’s going to be finished in a week.
"Off the record there’s a much bigger picture than that – than where the manufacturer’s controlling the total supply of engines within the sport… is that healthy?"