His attendance next week at the public inquiry in Elephant and Castle, south London, is certain to draw crowds of hostile protesters.
Proceedings will be accompanied by a level of security not seen since the appearance of the five murder suspects at the beginning of July.
Sir Paul did not testify to the first part of the inquiry, despite the scathing criticism made of his officers who investigated Stephen's murder in south-east London in 1993.
But on 1 October he will appear before Sir William Macpherson of Cluny, the chairman, to be questioned on the Metropolitan Police's submission to the inquiry's second phase, which aims to identify the lessons to be learned from the Lawrence case.
Sir Paul will be accompanied by Denis O'Connor, Assistant Commissioner in charge of community issues, and Deputy Assistant Commissioner John Grieve, recently appointed to head a new taskforce on racial and violent crime.
The Commissioner has faced mounting internal and external pressure as a result of the devastating tale of police incompetence exposed by the inquiry, and allegations by the Lawrence family that the investigation was blighted by racism and corruption.
The Met's commitment to combating racial crime has been called into question by two other high-profile cases: that of Ricky Reel, a young Asian who drowned in the River Thames, and that of Michael Menson, a black musician who died of his injuries after being found on fire in a London street.
The families of both victims say that police failed to investigate their deaths properly, discounting the possibility that they were murdered by racists. An inquest jury decided last week that Mr Menson had been unlawfully killed.
Mike Bennett, chairman of the Metropolitan Police Federation, which represents lower and middle ranks, last week called on Sir Paul to resign, saying that morale was so low that the force needed someone new at the helm.
At the office block where the Lawrence inquiry sits, Sir Paul will run the gauntlet of angry demonstrators.
The public gallery will be packed for the spectacle of London's most senior police officer being quizzed by Sir William and his three advisers.
Stephen's parents, Neville and Doreen Lawrence, who have repeatedly called on the Commissioner to testify to the inquiry, are certain to be present.
Sir Paul, who in a speech soon after his appointment in 1992 pledged that the Met would be "totally intolerant" of racially-motivated crime, is expected to tell the tribunal that his 10-page submission represents an ambitious agenda for reform.
He believes the policy initiatives will be a stepping-stone on the road to regaining the confidence of London's black communities.
It is 17 years since a commissioner has been called upon to account for the actions of his officers in a similar forum. David McNee gave evidence to Lord Scarman's inquiry into the 1981 Brixton riots.Reuse content