Michael Schumacher insists Ferrari are serious championship contenders again and aims to prove his point at the Nurburgring this weekend.

Schumacher won his first genuine race since 2004 with a narrow victory at Imola two weeks ago to move into second place in the world championship.

He returns to Germany for Sundays European Grand Prix buoyed by that success, and determined to silence the doubters who claim Ferrari's Imola success was a Bridgestone-inspired one-off.

Schumacher said: "The win gave us that extra motivation. To be honest, it was a plus after the races in Malaysia and Australia - ones that did not go as expected.

"It was great to see that everyone's hard work bore fruit and that we were right to believe we could be competitive at Imola. As we have often stated, I think that we can do just as well at Nurburgring.

"The Imola display proves that Ferrari are able to compete. I do not believe that things are as they were last year, where Imola was a ray of light, or like the year before that in which we dominated.

"I believe we are able to perform as we did at Imola for the whole season, though this will naturally be influenced by the various types of circuit.

"We should be competitive once again. I will obviously do my best. I hope to get a good result for our fans."

World champion Fernando Alonso is among those who still question Ferrari's genuine speed, despite being beaten to the chequered flag by Schumacher at Imola.

The Enstone-based Renault F1 team driver remains wary of the former champion but retains complete confidence in his car to put him back on top.

He said: "What we don't know at the moment is how consistent Ferrari will be. So far, they have been strong at the same tracks as in 2005, and not so good at others.

"It is too early to say if it will be the same this year, so we can't write them off and Michael is racing in front of his people too.

"We must concentrate on our job though, at Renault. I have the new engine, which is a good step forward, and there are new developments on the car at every race.

"So I am sure we can be fighting for the win again on Sunday."

Alonso was the only Renault at the front at Imola as a result of team-mate Giancarlo Fisichella's qualifying mistake. Fisichella qualified down in 11th but has vowed not to repeat that failure this weekend.

The Italian said: "It is frustrating but we know we lost the chance of a good finish in qualifying. We made some mistakes, and it won't happen again."