McLaren: Button and Alonso the preferred line-up for 2016

Jenson Button is the frontrunner to partner Fernando Alonso at McLaren for the 2016 FIA Formula One World Championship, according to the team’s racing director Eric Boullier.

McLaren have an option to keep Button for a further year, and while they have yet to guarantee his future, Boullier says the decision on next year's line-up will be taken quickly, in contrast to last season’s talks.

"There is obviously a date for the option on Jenson and we know that we will not wait for the end of the year this time,” Boullier told Formula1.com, confirming that Button is on a one-year contract with a possible one-year extension.

The matter is complicated by the fact McLaren have Kevin Magnussen - who raced for the team in 2014 and only narrowly lost out to Button in the fight for a drive this year - and Stoffel Vandoorne, the runaway leader of this year's GP2 championship, waiting in the wings.

"So far we intend to keep both the (race) drivers we have - but I am not the only one to decide," continued Boullier, adding, "For Kevin and Stoffel we will do the maximum that we can for them to race in F1."

Vandoorne said in July that his record-breaking performances in GP2 had proved he was ready to make the step up into F1 racing, while Magnussen recently insisted he would not be prepared to countenance another season on the sidelines in 2016.

Button, world champion in 2009 and a McLaren driver since 2010, has stacked up very well against Alonso this season, with a 5-6 record in qualifying against his team mate - although a litany of technical issues and penalties has affected both men. The Briton has also scored points twice, coming home eighth in Monaco and ninth in Hungary.