F1 teams reluctant to make Silverstone young driver test four days

The test, which takes place from July 17-19, has taken on increased significance with race drivers allowed to take part to help in tyre development work.

Pirelli is also planning to use the test as a first trial for its new tyres, which feature the 2012 construction and 2013 compound and will be raced from the Hungarian Grand Prix.

The FIA has said it would be willing to expand the test in to a fourth day if required, but the move has not been embraced by all teams.

Following discussions in Wednesday's Sporting Working Committee meeting at the Nurburgring, AUTOSPORT understands that some outfits did not wish to run an extra day on cost grounds - and there are also issues regarding there being enough supply of the new Pirellis.

It is understood that only Ferrari is still pushing for the test to be expanded, because of the importance of the test for both car developments and tyre work.

Teams have also agreed that race drivers will only be allowed to conduct one full day of testing at the test - with two of the days still reserved for young drivers.

It is believed, however, that teams may be able to run their two race drivers for a half day each, should they wish for both their men to try out the new tyres.