With seven races to go, McLaren currently holds the position on 83 points, while engine partner Renault has gathered momentum and is on 65 points after making a net gain of 25 over the Spa and Monza weekends.

All teams face the usual decision in the coming of weeks of when and how to switch their R&D focus from 2019 to 2020.

In McLaren's case, the fact that the MCL35 will be the first designed under the leadership James Key means that it is likely reflect a fresh approach and thus be less evolutionary than the new cars of some of its rivals.

Seidl says that despite the pressure from Renault in the fight for fourth McLaren will not change its schedule once it has been finalised.

"We plan to continuously bring in small things for the next two or three races at least," said the German.

"Then again we just have to see when we fully switch to next year's car on the development side. It's still something which is open.

"Of course we want to fight for this P4 as long as possible, but at the same time for me it's a lot more important to make the next step with next year's car, so I don't want to compromise next year by suddenly switching the focus on this year again.

"We have a plan in place for what we want to do this year, we have a plan in place for how we want to approach next year. Again, this is how we approach it."

McLaren was outpaced by Renault at the low-downforce venues in Belgium and Italy, but Seidl says it's impossible to predict what way the advantage might swing in the remaining seven races.

"I think it's so difficult to judge this year," he said. "I think it's not just for us, it's for every team in the midfield.

"It's so depending on the track characteristics, the tarmac, the temperatures you're seeing, the way how you can set up the car, in which window you have to run the car for the different tracks.

"As we have seen for example in Budapest where we expected to struggle more we have suddenly been the fourth fastest car. So difficult to judge, to be honest.

"But with all the updates we've brought to the more normal downforce package before the break, and updates we still bring now also for the next race, we hopefully can keep up the fight for P4 until the end of the season."