Sir Jackie Stewart has predicted that Lewis Hamilton will find life more difficult in his second season in Formula One than in his first.

The veteran Scot was impressed with the manner in which the young Englishman performed during his debut year on the Grand Prix circuit but believes that his team, McLaren, have been adversely affected by the FIA's lengthy investigations into their con-troversial possession of plans belonging to rivals, Ferrari, which led to them receiving a $100m fine from the world governing body.

"It's not unusual for a new GP driver like Lewis to struggle a bit in the second season, because he is no longer an un-known quantity," said Stewart, in looking ahead to the new campaign which begins in Melbourne next month. "He is in the position where people are expecting him to win every race he starts, and although I have no doubt that he will be competitive, I wonder whether he will have the car to take on Ferrari in 2008.

"It's a curious thing: Lewis will think he can nail this year's championship, because he came so close last time around, but that can make you push too hard, and, before you know it, little things can start going wrong which make the dif- ference.

"It doesn't help that McLaren have suffered so much disrup-tion as a consequence of the FIA's investigations. Team manager Ron Dennis' position has been threatened, he has lost the services of two-time world champion Fernando Alonso who has gone back to Renault, and now he has to try and refocus with a couple of youngsters in Lewis and Heikki Kovalainen.

"I know that McLaren will insist it is business as usual, but they have had to deal with all kinds of external issues, including the racist abuse which Lewis faced in Barcelona and, no matter how professional you aim to be, these matters all deflect a team from their prime concern, which is putting together the best car.

"None of this changes my opinion that Lewis Hamilton is an extremely talented young man, who has the ability and the attributes to win the F1 title, but a lot of factors have changed this season and Kovalainen's arrival at McLaren could mean that the shoe is on the other foot.

"Suddenly, here is another bright-eyed, bushy-tailed contender and, if Heikki makes a good start in the first few races, the publicity and press attention might revolve round him.

"Apart from that, I think Alonso will be determined to get rid of the bad memories of 2007, and his return will definitely boost Renault's fortunes, while Ferrari are in the pleasant position of going into the new season with the best all-round driver package - reigning champion Kimi Raikko-nen and Felipe Massa - and with the luxury of preparing for the defence of their title on their own terms and out of the spotlight.

"McLaren, at the moment, are under scrutiny in everything they do and everywhere they go. So they really need to keep their heads down and concentrate exclusively on racing affairs in the months ahead if they are to improve on 2007."

Stewart has few equals in his vocation as a sharp-eyed observer of the minutiae which so often spell the difference between success and failure. In his view, Hamilton enjoyed the benefits of competing in the No.1 vehicle on the grid last season, yet was ultimately unable to capitalise on his early supremacy.

"All McLaren's difficulties caught up with them in the last two GPs and they allowed the opportunity to slip away," said Stewart. "I wouldn't write them off, but it might be hard to build up that momentum again."