Triple world champion has been short of luck this season and trails championship leader Sebastian Vettel by 20 points.
Toto Wolff: Mercedes have 'let down' Lewis Hamilton's Formula One title bid
Mercedes-GP team chief Toto Wolff has issued a rallying cry for Lewis Hamilton's title bid after another dose of bad luck cost him points in Sunday's Austrian Grand Prix.
The Austrian boss, who saw Valtteri Bottas claim his second win of the year for Mercedes and move into contention for the drivers' championship, said Hamilton had suffered from a run of misfortune.
"In my opinion Lewis had all the bad luck that you can have," Wolff said.
"We've let him down with the head-rest, we've let him down with the gearbox. Now it's about time to fight back and hopefully that's going to happen in Silverstone."
Hamilton was deprived of a near certain victory in last month's Azerbaijan Grand Prix when he was forced to pit for repairs to a loose head-rest and had to start Sunday's race at the Red Bull Ring from eighth on the grid due to an unscheduled gearbox change.
Championship leader and four-time champion Sebastian Vettel of Ferrari finished second and extended his lead ahead of the Briton to 20 points, with Bottas 19 points adrift in third.
"I feel that he didn't have a great time most recently," Wolff said.
"He didn't have a great time in the race because he was suffering from the car and the tyres, he didn't have a great time with the gear-box troubles and the headrest.
"So it's about time that this changes. The momentum goes in the other direction ... Lewis is still right in the fight.
"It's not even half time in the championship and there are 275 points still to be won. Our target will be to let him fight back in the best possible way in Silverstone."
Hamilton was in downcast mood after Sunday's race, but is certain to recover his poise and be back to his best for his home race this week when he will bid to put recent setbacks behind him.
Vettel's good fortune - in escaping a heavy sanction for his 'road rage' attack in Baku and profiting from Hamilton's difficulties - has enabled him to enlarge his advantage, but without winning a race.
"Twenty points behind is 20 points," Hamilton said.
"It's not great. But it could have been 30. I don't think there's a call for me to do anything else than I'm already doing.
"It's not like the team aren't on my side or they're not working hard or I'm not pushing them hard enough. I just have to keep driving the way I have been and hope things get better."
Vettel, who declared that Bottas was 'un-human' if he had reacted to the lights-out to deliver his perfect start from pole position, appears to be enjoying a streak of good fortune.
This was highlighted again on Sunday when, as the 'silly season' rumours about the F1 transfer market began early, Ferrari chairman Sergio Marchionne revealed that the team were keen for him to stay - and had left it up to Vettel to sign a new contract when he is ready.
The German will be out of contract at the end of the season, but Marchionne revealed in Austria that he wants him to stay.
"I made it very clear that, if he wants to stay, then we'll just renew it. It's up to him," he said.
Vettel has said that he delayed contract talks to focus on the championship.
Defending champions Mercedes stretched their lead in the constructors' standings to 33 points and have won more races than their Italian rivals this year - by five to three, with Red Bull Racing claiming the other.
Red Bull are expected to be major contenders for victory at Silverstone next Sunday and a more intense scrap as the season reaches its halfway point with the 10th of 20 races is in prospect.