Labour has agreed to pay "substantial" damages to seven former employees who sued the party in an anti-Semitism row.
It has issued an unreserved apology in the High Court after agreeing to settle a defamation lawsuit by seven whistleblowers who spoke out in a BBC Panorama programme last year.
They said efforts were made to damage their reputation after they criticised the then leadership's response.
Labour said its actions had caused "distress, embarrassment and hurt".
In the July 2019 programme, entitled Is Labour Anti-Semitic?, a number of former party officials alleged that senior figures close to the leadership at the time had interfered in the process of dealing with anti-Semitism complaints.
They also claimed they had faced a huge increase in complaints since Jeremy Corbyn became leader in 2015.
In response, a party spokesman denounced them as "disaffected former staff" who had "personal and political axes" to grind. They were also accused of trying to undermine Mr Corbyn.
Seven of the whistleblowers took legal action and asked the Labour Party formally to apologise in court.
In a statement read out in the High Court, Labour said it unreservedly apologised and was determined to root out anti-Semitism in the party and the wider Labour movement.
"Before the broadcast of the programme, the Labour Party issued a press release that contained defamatory and false allegations about these whistleblowers," the party said.
"We acknowledge the many years of dedicated and committed service that the whistleblowers have given to the Labour Party as members and as staff. We appreciate their valuable contribution at all levels of the party.
"We unreservedly withdraw all allegations of bad faith, malice and lying. We would like to apologise unreservedly for the distress, embarrassment and hurt caused by their publication. We have agreed to pay them damages."
Some allies of Mr Corbyn, who stood down in the Spring after four years leading the party, urged his successor to fight the case.
The BBC's Laura Kuenssberg tweeted that "last minute legal wrangling by lawyers for some of former Labour leadership team didn't stop the apology and settlements going ahead".
The party's new leader Sir Keir Starmer has been anxious to emphasise his commitment to root out anti-Semitism, committing to implement in full the recommendations of an inquiry by the equality watchdog into Labour's culture and internal procedures due out in September.
He recently sacked Rebecca Long-Bailey from the shadow cabinet for re-tweeting an article containing what he regarded as a conspiracy theory.