Pirelli has indicated that it wants to test its new, wider tyres in a hotter climate on definitive 2017 cars, which will feature much higher levels of downforce than the mule cars currently doing the prototype testing.

Pirelli believes that, despite the higher loadings seen at Barcelona, it has to run its new tyres in hot conditions in order to fully explore the limits.

The teams had booked Barcelona for the two four-day tests, but Mercedes has been pushing for a move to Bahrain, with Niki Lauda personally lobbying rival teams.

Cost issues meant that Mercedes originally had limited support, but several teams have now come out in favour of the Bahrain option.

One source told Motorsport.com that Bahrain provides "more bang for the buck," with the obvious extra benefits of being able to test cooling systems in hotter conditions, and a guarantee of dry running.

Under the FIA regulations a majority of teams have to back any plan for a test outside Europe, and the teams who want Bahrain have signed a letter to Charlie Whiting confirming their support.

It is understood that those now supporting Mercedes include Ferrari, McLaren, Renault, Haas and Force India, with Red Bull and Williams among those still standing firm on Barcelona.

The letter from the former group reads: "We the undersigned agree to the two pre-season team tests for 2017 according to Article 10.6(g) of the F1 Sporting Regulations (Testing of Current Cars) to be conducted at the Bahrain International Circuit (BIC).

"Since the BIC is outside Europe we submit our request agreement according to Article 10.6(d). We make this agreement in support of the request from Pirelli for more representative track testing of the new tyres for 2017."

Parallel testing

Originally, a straight choice between the two venues was being discussed.

However, although in theory the rules don't allow it, the FIA is now also open to the possibility of two parallel tests running and the teams deciding which venue to attend, and that Whiting said at tonight's drivers' briefing that those are the three options.

A first test in Barcelona followed by one in Bahrain is not thought to be on the agenda.

With the tests running in parallel, that could open up the possibility of seven new cars running for the first time in public at 9am local time in Bahrain on February 27th, with the other four appearing later the same day in Barcelona, leaving the world's media with a choice of which venue to attend.

It is understood that Whiting will discuss the Bahrain plans further with Pirelli boss Paul Hembery tomorrow, before a meeting of team bosses on Sunday.

Mercedes' Paddy Lowe is adamant that the teams have to support the tyre company's request to run in Bahrain.

"The situation is that we have the biggest change in tyre regulations probably for one or two decades, and Pirelli have asked the FIA if they would support testing in Bahrain, which is outside Europe," said Lowe.

"For me, the important point that Pirelli were asking for is some hot condition testing of the compounds particularly.

"And unfortunately the mule car programme which is running at the moment has delivered three cars which are very helpful to the process, but they are not delivering the level of aerodynamic load that will be seen next year.

"So for me it's a matter of supporting Pirelli's request to contain the risk of arriving at the first race as being the first event with hot conditions and there's real risk to the show.

"We've seen what can happen, for example, in Indianapolis 2005. We mustn't forget that we need to put on a show, we need to run a 300kms race with sensible numbers of tyres, so that's not an inconsiderable risk and should be covered.

"So that's why we particularly support that request."

Meanwhile, Pat Symonds of Williams made it clear that his team is still opposed to the idea.

"The cost of doing a test outside of Europe is vast," said Symonds.

"Depending on exactly how you do it and how much you have to ship back to the UK, how much you can ship on to the first race – we're talking of a minimum of £300,000, probably a maximum of £500,000 so a likely figure sitting in the middle of that.

"Now to a team like Mercedes, I'm sure that they can put contingencies in their budgets to cover things like that. A team like Williams simply can't, it's a significant amount of our budget, it is unaccounted for and therefore I think it is the wrong thing to do."