Talks collapse regarding lifting Formula 1's engine freeze

The championship-winning Mercedes team had spent the last week evaluating whether to accept a one-off relaxing of the homologation rules to allow a mid-season upgrade next year.

But after analysis of the implications of the rule changes on its overall costs and the impact on its customers, Mercedes decided it could not go ahead with the proposal to allow 13 development tokens to be used next July.

Instead, it offered a compromise deal that would allow just five tokens to be used in July - something that its rivals rejected as not enough.

The matter means that for now the engine freeze rules are staying in place for 2015, and there is now only limited time to find a deal before an F1 Commission meeting takes place later this month.

Speaking about the outcome of the meeting, Mercedes motorsport boss Toto Wolff said: "We offered a slight compromise, which we think we could afford to not change the specifications and the price for the customers.

"We think what is essential in the current environment is not to increase the costs for anybody - the smaller teams or the customer teams. But that was not accepted."

RIVAL TEAMS CONSIDERING OPTIONS

With Mercedes' rivals convinced that the engine rules need to change for 2015 if they are to close the gap, they will likely keep up a push for something to change.

One option that has been suggested is for Mercedes' rivals to agree on even more relaxed rules for 2016, because majority support among the Strategy Group and F1 Commission would be enough to get the regulations changed.

Red Bull boss Christian Horner hinted that he did not believe the matter was completely finished.

"Nothing is changing, for the moment," he said.

Wolff added: "I am not sure it is the end. Maybe there will be new discussions, or follow up discussions."

However, Wolff urged against any move to get rid of engine development restrictions completely as it could theoretically be pushed through for 2016.

"That would be irresponsible to the sport and disrespectful of the teams who went out," he said.

"As Mercedes this would be not something that we think is an intelligent way forward."