McLaren managing director Jonathan Neale has revealed that his team's drivers, Lewis Hamilton and Jenson Button, will have the ultimate say on whether to use the blown diffuser in this weekend's race.

The British team is introducing a number of upgrades for this weekend, most notably its version of the blown diffuser, pioneered by championship rivals Red Bull. However, speaking in a phone-in press conference, Neale has revealed that after trying the upgrade in Friday practice the drivers will be allowed to decide whether to retain it for the remainder of the weekend.

"We would like to take it this weekend and, and if the drivers think it's good enough, it will stay on," he said. "If not, then we will continue to develop the upgrade.

"In Formula 1 it's rare there are 'golden bolts' that will transform your car from uncompetitive to competitive," he continued. "Most teams, including Red Bull, made an impressive change to their diffusers to give them a good step forward. It's one of the things we are working on as part of a package of changes that we are bringing to the next race and subsequent races. A lot of teams upgraded their cars quite heavily in Valencia, we've been trying to pull forward a variety of packages we have planned through the season.

"Friday will be a testing day," he added. "A number of teams are working with complex projects like blown diffusers and f-duct systems, there are a lot of installation issues which require track time to get right. I'm confident that we've made a reasonable performance step. Do I think we've got everything we've expected? It's hard to tell at this stage, I'll wait and see what the drivers think."

Whatever the outcome this weekend, Neale revealed that his team - which heads the standings in both championships - will have an upgrade of "reasonable size" in time for the German GP in tow weeks time, admitting that "all upgrades are in the concept stages".