We have to beat our competitors and need to gain more points than them every time Kimi Raikkonen

And the Finn says his team cannot afford any more slip-ups as they try to narrow the lead built up by McLaren's Lewis Hamilton and Fernando Alonso.

"Looking at the times [from testing], I think you can say that we have a fierce fight ahead of us," he said.

"All the upcoming races are crucial - can't make any more mistakes."

Hamilton leads the championship heading into Sunday's race on the historic Monza track.

The Englishman has a five-point advantage over world champion Alonso, 10 over Ferrari's Felipe Massa and a further one over Raikkonen with five races to go.

606: DEBATE We have 4 drivers who are the approximate equal of each other, with Hamilton slightly edging the others in consistency purpleDogzzz

McLaren have an 11-point lead in the constructors' championship.

The teams appeared closely matched when they tested at Monza last week, and Raikkonen admits that Ferrari need to repeat the one-two they achieved in Turkey last time out.

"The team gives 110% and we have to beat our competitors and need to gain more points than them every time," the 27-year-old said.

And he said he was looking forward to racing in front of the fanatical Italian fans as a Ferrari driver for the first time following his move from McLaren last winter.

Ferrari trail McLaren despite a one-two last time out in Turkey

"It will be really special to feel the heat of the tifosi," Raikkonen said. "I can't wait to see all the flags with the Prancing Horse on the grandstands."

The race takes place in the shadow of the two forthcoming hearings McLaren face in front of the sport's governing body, the FIA.

On 13 September they appear in front of the FIA court of appeal in relation to the "spy" saga, which saw them escape punishment despite possessing confidential Ferrari documents.

And on 19 September McLaren will appeal against the decision to dock their constructors' points from the Hungariam Grand Prix following a dispute in qualifying between Hamilton and Alonso.

The Spaniard said he wanted to bury memories of last year's Monza race, when, driving for Renault, he was controversially dropped to 10th on the grid after being accused of holding Massa up in qualifying.

"The Monza track is unlike any other we race on during the season, - it is all about high speeds," said Alonso.

Monza is a historic circuit, so it is quite special when you go there for any driver Lewis Hamilton

"The cars always feel different, very light and not always under control to be honest, which is because of the low downforce we use to get the high speeds.

"But we spent time testing on the track last week and we had some good feedback, so I feel positive going into the race.

"It is a challenge, but it is a special circuit and it is a great feeling to race here.

"Last year, though, did not give me any good memories, so it is a track that I would really like to win at."

Hamilton added: "Monza is a historic circuit, so it is quite special when you go there for any driver. It is a great track.

"I had my first race there last year in GP2, and it was a very memorable weekend because it was where I won the championship.

"I also had an awesome battle with Giorgio Pantano for the whole of the Sunday race, which was one of the most enjoyable for me all year.

"Hopefully this year I will have just as good a race and great memories for the future."