Lewis Hamilton has been urged by survivors of the Grenfell Tower disaster to condemn his own Mercedes team after they refused to bow to public pressure and end ties with cladding firm Kingspan.
The seven-time world champion was sent a letter by the Grenfell Next of Kin support group saying he had "blood money" on his hands, that he was on the "wrong side of history" and that he would be "held accountable" if he failed to speak out.
The letter came after housing and communities secretary Michael Gove warned Mercedes that ministers could re-write the rules on advertising on racing cars if they pressed ahead with the deal.
"I am conscious that there are very real questions about whether Parliament would support a statutory regime that enabled a core participant in a public inquiry in to how 72 people lost their lives to advertise its products publicly to millions of families across the country," Gove wrote in a letter.
"The achievements of Mercedes and Sir Lewis Hamilton in recent years represent a British success story of which we are all proud. I hope you will reconsider this commercial partnership which threatens to undermine all the good work the company and sport has done."
Mercedes are so far holding firm. After spending much of Friday formulating a response, the team eventually published a letter from team principal Toto Wolff responding to a separate, equally stinging letter from the Grenfell United group.
Wolff said he wanted to "apologise for the hurt" that the Kingspan announcement had caused them.
The Austrian added, however, that prior to signing the deal the team had "engaged with Kingspan in depth to understand what role their products played in what happened at Grenfell" and that Mercedes were satisfied that Kingspan's hands were clean.
"Kingspan have stated that they played no role in the design or construction of the cladding system on Grenfell Tower, and that a small percentage of their product was used as a substitute without their knowledge in part of the system which was not compliant with building regulations and was unsafe."
Wolff did agree to Grenfell United's request to meet in person to help him "learn and understand better" about the disaster.
His response is unlikely to appease survivors and relatives of the disaster, which tragically claimed the lives of 72 people on June 14 2017.
'Do the right thing - be a hero'
The Grenfell Next of Kin group strongly dispute Kingspan's claim to be innocent in the disaster. In a letter addressed to Wolff and Hamilton the group described the multimillion pound deal as "blood money".
"We've spent 4.5 years listening to evidence and analysing this cesspit," they wrote. "You have made an error in judgement. Before you pop the champagne cork remember you have the power to choose where we did not and do not.
"All we have is the system to hold these companies accountable. You're not helping. You're harming. And for that you too will be held accountable. Do the right thing. Turn down the sponsorship. Don't be an Uncle Tom F1. Be a hero."
All eyes will now be on Hamilton to see whether he will respond. The 36-year-old is attempting to secure a record eighth world title this year, and enters the penultimate race of the season trailing Red Bull's Max Verstappen by just eight points in the drivers' championship.
But he also has a well earned reputation for speaking out on sensitive issues. Hamilton has been a vocal supporter of the Black Lives Matter movement in the last 18 months, and this week spoke up in support of LGBT and women's rights in Saudi Arabia, admitting in his press conference on Thursday that he was "uncomfortable" racing in the country.
Hamilton has previously supported the Grenfell community as well. On the third anniversary of the fire, he posted on Instagram: "Today marks three years since the horrific Grenfell Tower fire in London. Remembering the 72 souls we lost and their loved ones, and everyone affected by this tragedy. #justiceforgrenfell."
It is unclear whether the world champion was aware of Kingspan's ties to Grenfell prior to the deal being made public on Wednesday. Or even of the deal itself. Mercedes stressed on Friday that drivers are not typically involved in sponsorship decisions.
Hamilton was not put up to media after the free practice sessions but is bound to be asked about it over the course of the weekend.