Schumacher has won just once this term - the farcical Indianapolis GP

Ferrari were never on the pace at the new Istanbul track and the German retired after an undistinguished race.

"Sadly we couldn't continue the form we showed at Hockenheim or Budapest and at no time were we competitive. We have, instead, taken a step back," he said.

Ferrari team boss Jean Todt agreed: "There was definitely no light (in Turkey). It was very dark."

Todt has now conceded any hope of retaining either the drivers' or constructors' championship.

"I've lost the dream to win both championships and now at least we have to secure third position if possible," he said.

Schumacher felt his fifth-place finish at the German Grand Prix in Hockenheim and his runner-up spot in Hungary had signalled a change in fortune for Ferrari.

I've lost the dream to win both championships and now at least we have to secure third position if possible Jean Todt

But the German admitted: "We have, instead, taken a step back."

After the disappointing experience in Turkey, the defending champions trail leaders Renault by 44 points in the constructors' standings.

Meanwhile, Schumacher lags 40 points behind Fernando Alonso in the drivers' championship.

However, Todt hinted that Ferrari's Bridgestone tyres were a major contributor to the team's problems at the weekend - and that is something to work on ahead of the next race in Monza, Italy, on 4 September.

Bridgestone supplied older-specification tyres for the inaugural F1 race in Turkey as their more promising new compound was unsuitable for the Istanbul Otodrom.

"We were using the same car in Budapest, when Schumacher was second, but with completely different tyres," he said.

"We saw that we were very quick in qualifying and we were very quick for the first third of the race, but then we started to drop performance so it gives us, and our partners, some indications."