Red Bull owner Dietrich Mateschitz has hit out at Renault for destroying his team's "enjoyment and motivation" and is ready to walk away from Formula One.
Relations between engine supplier and team have been fraught since rule changes introduced new power units into the sport from 2014.
Before then, the pairing had provided Sebastian Vettel with the machinery to win four world championships in succession.
But Renault missed a beat with the new regulations and have been playing catch-up ever since, with team boss Christian Horner also vocal in his condemnation of the lack of competitiveness in the Renault power unit.
The French manufacturer has threatened to withdraw from the sport and Mateschitz, ahead of Sunday's race at Red Bull Ring in the team's home country of Austria, has once again put pressure on Renault - although he did play down any chance of switching to Ferrari power for 2016 saying there was "no alternative to Renault" for next season.
"Beside taking our time and money they have destroyed our enjoyment and motivation," he told Speedweek.
"No driver and no chassis in this world can compensate for this horsepower deficit. How many more things have to happen before we lose all enjoyment?
"In addition, our chances were so scuppered by aerodynamic regulations which meant that chief designer Adrian Newey could not weave his magic on front wings. Now we have used our fourth engine, which means we are penalised on the grid."
Red Bull won three races in 2014 as Daniel Ricciardo managed to wrangle victories from the dominant Mercedes pair of Lewis Hamilton and Nico Rosberg in Canada, Hungary and Belgium.
This year has been more of a struggle and Mateschitz conceded he could pull the plug on the team's F1 project before their contract expires in 2020.
"There are contracts for Formula One participation," he added.
"How many teams have dropped out of Formula One, despite already (having) contracts? You cannot hold someone if he wants to get out."