Sebastian Vettel believes Mercedes are the favourites for this weekend's Belgian Grand Prix as the title battle resumes following the summer break. 

Vettel was the comfortable victor last time out in Hungary, but the famous Spa-Francorchamps circuit is expected to favour their chief rivals, who enjoyed a slight advantage at power-sensitive circuits, notably Silverstone where Mercedes enjoyed their most dominant weekend of the 2017 season.

The German acknowledges that the Silver Arrows may well have the upper hand, but has vowed to "attack" as he looks to defend the 14-point championship lead he holds over nearest challenger Lewis Hamilton.

"There are some similarities [between Spa and Silverstone], obviously, but there are some things that are very different, so we'll see," he said. "I think if we had to race at Silverstone again, we would do a lot better as we just didn't get a very good weekend altogether. It's true that Mercedes is very strong there.

"It's true that Mercedes is very strong there and the fact that it's likely to be similar here, obviously for us makes it fairly straightforward. I think we have only to gain.

"Because of how strong they were at Silverstone and some similarities, I would say they are the favourites coming here but for sure we're not going to settle behind them. We're going to attack, and we'll see what we can do."

Vettel's efforts will be boosted by a significant upgrade package as Ferrari introduce a new front suspension, which includes a third damper, as well as tweaks to their floor and wings to cope with the low downforce required at the Belgian track.