At 19 years and 125 days of age, Jaime Alguersuari may be set to become the youngest F1 driver in the world championship's official 60-year history in this weekend's Hungarian Grand Prix in Budapest - but the Spaniard's rivals are unconvinced that he is up to the challenge, insisting that he is 'too young' and that his promotion is 'not right', adamant that the top flight is 'not a learning school'.

Alguersuari will graduate from the World Series by Renault - in which he is a front-runner with Carlin Motorsport - to fill the empty Scuderia Toro Rosso berth vacated by record-breaking former multiple Champ Car king S?bastien Bourdais following the German Grand Prix at the N?rburgring a fortnight ago.

However, due to the new in-season testing ban the reigning British F3 Champion has conducted just two straight-line tests in the car, and as such, contend some of the current members of the grid, he is far from ready or adequately prepared to make his bow at the Hungaroring.

"For me, he's too young," asserted Ferrari ace Felipe Massa, who himself made his debut at the highest level aged just 20 with Sauber-Petronas back in 2002, subsequently needing to take a year out as a test driver for Ferrari after finding it too much, too soon given his lack of experience.

"When I came into Formula 1, I was too inexperienced to ask for what I needed from the car and I did not know what to expect, so I made some mistakes. For sure I had a very difficult car to drive, but anyway, it was not easy for me.

"It was too early for me, but the difference is that at least I had spent the winter doing lots of testing in Formula 1. He does not have this experience. He's never driven a Formula 1 car, or he has driven it in a straight line or whatever.

"For me it's wrong. He can burn himself very quickly. Maybe he's an incredible talent and he will do much better than everybody thinks, but for me it's not good for him. I'm surprised a team would put a guy like this in the car. For me it's not right."

Current world championship leader Jenson Button - another young debutant, aged just 20 when he took the starting lights for the first time with Williams nine years ago, albeit following a long winter of testing beforehand - admitted that he could not criticise or blame Alguersuari for seizing the chance presented to him, but warned that it 'could absolutely destroy his career'.

"I don't know the reasons for him getting the drive," added the Brawn GP star. "I can guess, but he's not going to help the team develop the car."

"When you arrive in Formula 1 you should be ready," echoed Red Bull Racing title rival Mark Webber. "It's not a learning school."

Defending world champion Lewis Hamilton was another early starter, but when he joined the field with McLaren-Mercedes back in 2007, he had benefitted from career-long support from the Woking-based outfit and a significant amount of time in the cockpit and on the test tracks - making him arguably the best-prepared rookie ever. Seat time, the 24-year-old underlined, is of paramount importance.

"In 2006, when [Juan-Pablo] Montoya left (McLaren), I was going to replace him and I'd only done straight-line tests, but it would have been the worst move of my career," the nine-time grand prix-winner cautioned. "It takes confidence and a lot of preparation. If I hadn't had that testing and I'd gone into China, who knows if I'd have got my drive the following year."

Alguersuari gained his FIA super-licence by dint of his British F3 crown last year, and double F1 World Champion and compatriot Fernando Alonso countered the general consensus in arguing that if the Barcelona native is good enough, he's old enough [see separate story - click here]. The man from Oviedo was also 19 when he joined the fray with Minardi in 2001.

"We can do a lot of laps on Fridays now," Renault's talisman driver pointed out. "Obviously he will maybe not be 100 per cent for this race, but it's a great opportunity and hopefully in a very short time he will be 100 per cent."