Stories are circulating widely that Lewis Hamilton could be about to jump ship for 2013 to Mercedes.
Paul di Resta, Kimi Raikkonen and even Nico Rosberg have been touted as potential candidates to replace the 2008 world champion.
But team boss Whitmarsh told Germany's Sport Bild: "I have no 'plan B', because I really think that Lewis is staying."
Some believe the long and rumour-filled negotiations reveal an impasse, but Briton Whitmarsh insists there is "no fundamental problem".
"Both parties want to continue to work together, we are just getting over a few details.
"I do think the negotiations will be completed soon," he added.