Mercedes Formula 1 driver George Russell has blamed running "slower than an F2 car" on the straight for his costly early exit from the Belgian Grand Prix, after contact with Lewis Hamilton.

Russell had laboured with an unspecified lack of straightline performance - which in the final segment of qualifying showed up in the second and final sector rather than the first - all weekend relative to Kimi Antonelli.

It had followed a pattern of underperformance relative to Antonelli for a considerable stretch of the F1 season, but while coming into the weekend Russell said he was working on his driving to reduce the gap, he said after Saturday that there was something fundamental and unrelated to driving style that was costing him against Antonelli.

Mercedes was in alignment, and ahead of the race team boss Toto Wolff said: "I really hope we've found the root cause on the engine. There is something we saw, hopefully should be gone today."

But Russell never got far enough in the race to offer a hint one way or another.

He struggled for speed on the Kemmel Straight after starting third, and ended up side-by-side with Lewis Hamilton for fourth coming through Les Combes - which resulted in contact and ended Russell's race in the gravel.

Hamilton was given a five-second penalty for the collision - but Russell made it clear he blamed the power loss rather than his former team-mate for what's transpired.

And he described it as "something totally different" to the power issues that had been plaguing him through the weekend.

"I made a good start. I made a great first corner and I was tucked up right behind Verstappen, but for whatever reason the battery decided not to recharge at Turn 1," said Russell.

"So I went round the first corner, the battery didn't charge and I exited the first corner and I was 35% down - and because of that, because it didn't charge, I also had a boost problem. The turbo didn't sort itself out, so I had no power.

"I got to the top of Eau Rouge with 0% on the battery. Quite frankly, it was dangerous.

"I got swamped by three cars. I shouldn't have been in that position in the first place, that's why I'm most angry."

He also told Viaplay: "I was going slower than an F2 car, I got overtaken by three drivers. Left me vulnerable."

On the Hamilton clash, Russell said: "Honestly, I think was a racing incident. He didn't do it on purpose.

"Yeah, he was more to blame than I am, but he didn't do anything reckless. That was one of those things, I'm just most angry with that I was in that position in the first place. I was in a great position out of Turn 1 and I was ready to fight the two guys ahead of me up to Turn 5.

"Instead I get swamped by three drivers."

Russell described himself as "numb to disappointment" at the conclusion of the race, with his deficit to the championship lead increasing from 25 to 45 after Antonelli's win.

Asked about the work to solve the issue from eariler in the weekend, he told Sky Sports F1: "Appreciate everyone is working hard to solve the problem - I'm stood here on lap five of the race and felt like I was in a good position to fight for the lead in Turn 1, and then suddenly no power and it's all gone."