Sir Keir Starmer has said he regrets calling Black Lives Matter protests "a moment" after being criticised for dismissing the campaign's importance.
Asked on Tuesday about calls to defund the police, the Labour leader said it would be "nonsense" in the UK, adding: "The Black Lives Matter movement, or moment if you like [is] broader".
Labour MP Florence Eshalomi said his "choice of words [was] wrong".
On Thursday, Sir Keir said recent protests had been a "defining moment".
Speaking at a Q&A with black journalists from the UK, he told the BBC's Rianna Croxford: "If people have thought [I] meant something else, then of course I regret that.
"This is not a moment for not standing with the Black Lives Matter movement and the injustice that is being exposed."
Black Lives Matter was founded in the US 2013 after the acquittal of George Zimmerman for the murder of black teenager Trayvon Martin.
The group has campaigned on a number of issues since, but rose to global prevalence again after the killing in the US of George Floyd, with multiple protests against racism in the UK under its banner.
It has made calls in the US to defund the police - arguing police departments' budgets should be slashed and funds diverted to social programmes to avoid unnecessary confrontation and heal the racial divide.
After Sir Keir made his initial comments on BBC Breakfast, some Labour MPs criticised their new leader.
Ms Eshalomi tweeted: "For the year 12 students I spoke to last Friday at Lilian Baylis School, where a number of the boys (and one girl) mentioned they had been stopped and searched, Black Lives Matter isn't a moment.
"[The] choice of words in the interview was wrong. I will continue to relay constituents' views to Keir."
'Centuries of injustice'
Bell Ribeiro-Addy also tweeted: "#BlackLivesMatter isn't just a moment, it's a movement.
"It's clear that if we want to see real change, it's going to take sustained pressure from below."
Jermaine Jackman, who ran for a place on Labour's National Executive Committee (NEC), also said he was "angry" at the comments, adding Sir Keir "never really cared about us or our voice".
The Labour leader was then questioned about his words by the party at a meeting of the NEC earlier this week.
Labour MP Nadia Whittome told BBC Politics Live on Wednesday that he had "clarified what he said" during the meeting, calling Black Lives Matter protests a "historic moment".
She added: "[The protests] came as a result of decades, or centuries [of] institutional racism and injustice towards black people. I think he does understand that."
Sir Keir's words come as the party calls for "action, not words" from the government to tackle racial injustice.
Labour criticised No 10's launch of a Commission on Race and Ethnic Disparities in June, saying numerous reviews had already been done, without their recommendations being put into place.
It has called for four "clear cut" recommendations to be made into law, namely:
- Ethnicity Pay Gap reporting - from the McGregor-Smith Review into race in the workplace
- The development of culturally competent occupational risk assessment tools, especially for key workers - from the Public Health England review into coronavirus disparities
- A national target to achieve a representative judiciary and magistracy by 2025 - from the Lammy Review into the criminal justice system)
- The creation of a Migrants' Commissioner - from the Wendy Williams Review into the Windrush Scandal
Labour's shadow secretary for women and equalities, Marsha De Cordova, said: "Across the board, the government has been told time and again what needs to be done, but has failed to do a decent job of taking action.
"We cannot wait any longer to address the deep-rooted systemic racial inequalities across our society."