The championship picture now appears a forlorn one for McLaren in the wake of Sebastian Vettel's Belgian Grand Prix win on Sunday, his seventh victory in 12 races this season.
Although Jenson Button produced a storming drive from 19th in the early stages at the Spa-Francorchamps circuit to claim a podium place, he trails Vettel by 110 points with 175 available.
As for team-mate Lewis Hamilton, he is a further three behind after crashing out on lap 13, his sixth in-race accident of a tumultuous campaign.
With regard to the constructors' championship, McLaren are now 131 adrift of Red Bull, yet Whitmarsh is refusing to be bowed by the situation.
"Probably a weakness at McLaren - and my own weakness - is I don't like not winning. I can't help myself," said Whitmarsh.
"So I'm always going to ask the guys at the factory 'How do we make the car quicker next week?', and for the time being we are going to keep pushing.
"There are seven races left and they are seven races we can win, which has to be the goal at the moment.
"The championship looks pretty ambitious, but for the moment we have to be positive.
"Also, the fans expect it. If Ferrari, or particularly McLaren, say 'we are going to freewheel now' I don't think that's the right message.
"I think the fans deserve a stronger battle than that."
Unlike Ferrari, who recently confirmed their primary focus is on developing next year's car, McLaren will continue to look at both sides of the coin.
"We're working on next year's car, but you review your emphasis all the time," added Whitmarsh.
"We had six performance modifications on the car at Spa, one of which came out of the development programme for next year.
"So you're always going to try and steal things from next year's car, which will happen.
"It's not a line you draw and say this is purely this year, and on the other side of the line is purely next year.
"You are learning and gaining this year that helps you gain next year, and occasionally you learn from next year's programme that you can use for this year.
"But I want the car to be quicker for the next race, and the race after that, and we are going to keep pushing for the time being."