Christian Horner has been accused of giving "racists an excuse to let fly their vitriol and evil" at Lewis Hamilton following his criticism of the Mercedes driver after Sunday's British Grand Prix.
Lord Hain, vice-chairman of the All Party Parliamentary Group on Formula One, believes Horner will "regret" the remarks he made in the wake of Hamilton's 180mph collision with Max Verstappen on the opening lap of the contentious Silverstone race.
Seven-time world champion Hamilton, 36, was subjected to online racist abuse – which started during the race and continued after the chequered flag had fallen.
Red Bull joined Mercedes and F1 in condemning the abuse on Monday, while team principal Horner also felt personally moved to post a message on social media, saying: "Whilst the rivalry is intense on track, highly-charged emotions should never cross the line into racist abuse".
But Hain, a Labour peer who lobbied for Hamilton's Knighthood and served as a cabinet minister in Tony Blair's government, told the PA news agency: "Racists had an excuse to let fly their vitriol and evil at Lewis after what I thought was a very ill-judged, intemperate and plain wrong attack on him by Christian Horner.
"I am not suggesting for one moment that Christian Horner was implying anything racist in what he said. He was talking in pure racing terms and not racist terms and that is obvious.
"But most Formula One drivers said that it was a racing incident. These are two absolutely top drivers battling for the crown and Lewis has had to give way to Max before when Max was being aggressive, and I think Lewis decided that this time he wasn't going to bullied out of the way."
Verstappen was in hospital for six hours after the accident, which registered at an extraordinary 51G. Hamilton was deemed to be "predominantly at fault" for the collision and he was punished with a 10-second penalty and awarded two points on his licence.
When asked if Hamilton's move at Copse – one of the fastest corners on the F1 calendar – put Verstappen's life in danger, Horner replied: "Of course. His actions have left in jeopardy another driver's safety and for me that is unacceptable."
He also described Hamilton's first-lap move as an "amateur and desperate mistake."
Hain added: "I hope it was something said in the heat of the moment when Christian was feeling aggrieved and that is understandable. But these are moments when leadership is required and not intemperate outbursts.
"Christian has shown a lot of leadership and maturity in his Formula One career, but his comments were eyebrow-raising.
"I couldn't believe this was the same considered, careful, articulate person that he normally is, so I am sure he will regret it."