Jerome d'Ambrosio says he is still working on securing a Formula 1 race seat in F1 for next year, but the Belgian admits the situation is not easy.
D'Ambrosio made his grand prix debut with Marussia last year but was left without a full-time race seat for 2012.
He was signed by Lotus as its reserve driver this year and returned to racing when he replaced Romain Grosjean at the Italian Grand Prix while the Frenchman was serving a one-race ban.
With only Marussia, Caterham, Force India and Lotus yet to confirm their second drivers, d'Ambrosio concedes it is hard to find a place on the grid.
"Not everything is confirmed yet. We're still working on it," he told AUTOSPORT. "It's tough. We'll see what happens. Time will tell.
"With the season finished, the remaining people who have everything in their hands will take their decisions.
"It's very difficult. There are a lot of drivers out there without seats. Some experienced ones, some less experienced ones.
"All I can say is that I really love Formula 1, I loved being on the grid last year even if it was not in a top car. I enjoyed being in the car at Monza very much. It's what I love to do and I will fight to stay in Formula 1 as long as I can."
D'Ambrosio said he is not willing to spend another year on the sidelines if he can't secure a race seat in F1.
But the Belgian, who tested a DTM Mercedes last week, will only weigh up his options elsewhere if he is ruled out of a grand prix drive.
"We will see at the time," he said. "For sure it's difficult not to be driving. If I have to do another year as a third driver, then we will see what I can do."