Stoffel Vandoorne says fellow McLaren reserve/development driver Kevin Magnussen won't be his only rival for a potential Formula 1 race seat next season as speculation grows about whether the current GP2 Series leader will secure an F1 drive for 2016.

The McLaren Honda test driver says he's in constant communication with Ron Dennis about his future but his primary target this season is winning the GP2 drivers' title.

The Belgian is targeting a step up into F1 in 2016 but with Fernando Alonso on a two-year deal, Jenson Button on a 'one-plus-one' contract and McLaren making little headway with the plan to create customer outfit using Honda engines, his path into the premier category is fraught with obstacles.

His former Formula Renault 3.5 Series rival Magnussen is in a similar position having lost his F1 race seat at the end of 2015 and is currently acting as test and reserve driver for McLaren this year.

The pair of young McLaren drivers work alongside one another at the team's base in Woking and Vandoorne says they know a lot about each other and what they are capable of.

Vandoorne, as a rookie, lost out to Magnussen for the Formula Renault 3.5 drivers' title in 2013, with the Dane going on to make his Formula 1 debut while Vandoorne switched to GP2.

"I have a lot of respect for Kevin as I raced with him in 2013 in World Series," Vandoorne said. "We both know each other's potential and capabilities. F1 is a competitive sport and I don't think only Kevin would be a rival for a Formula 1 seat next year as there are others around and others I race in GP2 that could be a potential challenger for a Formula 1 seat."

Despite the pair fighting for potentially the same F1 spot Vandoorne says there isn't any friction between the two drivers and hopes they can use the competition to help drive one another further.

"Kevin is one of the good guys and I know him from the past," he added. "Even if I win the GP2 championship this season there is no guarantee that I will be in Formula 1 next year but I am pushing really hard to try to get there next year."