LONDON, England - Sebastian Vettel's winning streak in F1 is becoming a bore and could be the reason why ticket sales for the 2013 British Grand Prix scheduled for June has slumped, organisers claim.The circuit's managing director, Richard Phillips, said ticket sales were down 10% compared to 2012 and a boost in form for Jenson Button or Lewis Hamilton would help to turn it around."Sebastian Vettel is doing extremely well and so is Red Bull."NEW WINNER NEEDED"Personally I think he's a great driver and I love Red Bull but it would be nice if the team didn't win all the time. I think the needle-movers are basically not going to be Vettel," said Philips.Reigning triple World champion Vettel has won two of the four races so far in 2013 and is leading the Drivers' championship from Kimi Raikkonen by 10 points.Another problem, Phillips said, was that the memories of the 2012 weather chaos - where paying spectators were actually turned away on qualifying day - were also hurting ticket sales."You know there's going to be a slight rebound because of that," he said. Stay with Wheels24 for the 2013 Formula 1 season – fresh reports every day.