Jenson Button is predicting a four-team scrap next season when he defends his Formula One world championship title.

The chequered flag may only have come down on this year's campaign on Sunday but already thoughts are turning towards 2010.

It promises to be a very different season for Button as he will go into it as the driver in the firing line.

As yet his future is uncertain, although he is expected to remain at Brawn GP, with manufacturing giants Mercedes-Benz set to take a 75% stake in the team.

If that happens, Button and Brawn will be no one-hit wonders and in a position to again fight it out with Red Bull, while a resurgence will be expected from McLaren and Ferrari.

Lewis Hamilton finished the year as the driver who scored the most points from the last eight races, with Kimi Raikkonen - who will be replaced by Fernando Alonso at Ferrari next season - close behind.

With the only major change for next season being a refuelling ban, Button said: "Ferrari and McLaren are going to be competitive.

"They have the resources, the expertise, competitive drivers, so for sure they are going to be quick.

"They've had a different approach over the last few races. If you look at Ferrari, they've said they've had no development.

"It is unusual to hear that as there's not much that changes for next season.

"But it seems McLaren have thrown everything at the car and have been very competitive over the last few races.

"So going into next year, they're going to be quicker compared to the start of this season.

"But I don't think they're suddenly going to be stronger than Red Bull and Brawn.

"I think there's going to be a big battle at the front, which is going to be a new thing for all of us.

"Having four teams, eight drivers fighting it out at the front for wins, that hasn't happened for a while. That's exciting."

Sebastian Vettel is confident his team have not expended too many resources and energy in fighting for this season's title, rather than focusing on next year's car.

That is what happened to McLaren and Ferrari a year ago, ensuring they were ill-prepared for the biggest rule changes in F1 for 20 years.

Vettel, winner of the season-ending Abu Dhabi Grand Prix ahead of Red Bull team-mate Mark Webber and Button, said: "We are a team and we are professional.

"You might read here and there that other teams stopped developing this year, looking ahead to next year.

"But the regulations aren't changing too much. The biggest change is no refuelling but other than that the cars will remain similar, similar shapes.

"The people know what they are doing back in Milton Keynes (at the Red Bull factory), so I'm very confident. I think we can only get stronger."