McLaren's team principal Martin Whitmarsh has said that he doubts Bernie Eccleston's suggestion of a total budget cap for F1 teams will prove to be workable in practice.

Ecclestone has revived his proposal of a cap as a replacement for the current Resource Restriction Agreement. The current RRA is opposed by Red Bull Racing, which has vetoed the agreement becoming part of the F1 sporting regulations and statutes and even led to Red Bull and Ferrari quitting the Formula One Teams Association (FOTA).

Red Bull is believed to be the biggest spending operation in the F1 paddock in 2012.

"Red Bull spends about $250m per season," Williams investor Christian Toto Wolff is quoted as saying by El Confidencial. He added that the team's owner Dietrich Mateschitz could save over a third of that amount by adhering to the RRA. "Though without their unlimited spending model they would not have the same advantage," Wolff pointed out.

However, Red Bull team principal Christian Horner has insisted that he's happy with his team's current level of spending. "We have been very consistent regarding resource constraints, and if that disturbs others, then that's their problem, not ours," he said.

At this week's meeting in Paris between Ecclestone and the F1 team principals, Ecclestone is said to have proposed setting a maximum total expenditure for all F1 teams in future. This would replace the RRA, which works by focusing on limiting specific items such as external expenditure, windtunnel time, and the number of staff on the payroll, but excludes other items such as driver salaries.

Ecclestone is said to have proposed the $250m (?155m) figure as the initial level of the cap, but that immediately provoked disagreement among the team principals.

"It sounds like quite a lot of money, so I don't know how much it's going to help too many teams," was the opinion of Martin Whitmarsh, Horner's counterpart at Williams.

Whitmarsh pointed out that only the top four teams in F1 came anywhere close to the $250m budget, which is far in excess of the budget of the small teams at the back of the grid like Caterham, Marussia and HRT. At that level, a cap would do little to achieve the much sought-after level playing field in the sport.

But even if a suitable budget cap could be agreed by all the parties, it was just the first of a number of significant details that would have to be addressed before the system stood a chance of achieving consensus.

"It becomes difficult to pin down and know everyone is comfortably operating within it," Whitmarsh told BBC Sport, going on to describe Ecclestone's plan as "a bit unrealistic" to operate in practice.

"The budget cap by Bernie is everything - everything you spend money on. Total cap," explained Whitmarsh. "It has the elegance that you can describe it very quickly but it is very difficult then to find out where that money is and to control it.

"Bernie wants one that controls driver salaries and all those things. I think what we should be trying to do is ensure we are spending money in the appropriate places," he continued. "I think we should be controlling excessive spend in development."

Horner's objection to the RRA is believed to be that teams associated with existing car manufacturers and technology companies like Ferrari, Lotus and McLaren could easily 'hide' some of their F1 expenditure in their affiliated operations in a way that other companies like Red Bull would not be able to. The same objection could be levelled at a global budget cap.

Engine development adds another wrinkle to the discussions. Ferrari and Mercedes both design, develop and build their own engines for F1 and then sell them to other teams, while Red Bull, Williams, Caterham and Toro Rosso purchase their engines from Renault, and HRT and Marussia have been using Cosworth units. How would a global budget cap allow for such varying requirements and capabilities?

The sport of F1 might be too complex, and the nature of the teams involved too varied, to allow even Bernie Ecclestone to design a one-size-fits-all solution to the issue of budget caps in the short term.