Sir Keir Starmer is the latest Labour MP to announce he is running for the party leadership.
The shadow Brexit secretary becomes the fifth MP to enter the race following Labour's worse general election performance since 1935.
Backbenchers Jess Phillips and Lisa Nandy declared on Friday, while while shadow foreign secretary Emily Thornberry and shadow Treasury minister Clive Lewis are also running.
Writing in the Sunday Mirror, Sir Keir said: "Over the coming weeks, I'm looking forward to getting back on the campaign trail and talking to people from across the country about how Labour can rebuild and win.
"Britain desperately needs a Labour government. We need a Labour government that will offer people hope of a better future.
"However, that is only going to happen if Labour listens to people about what needs to change and how we can restore trust in our party as a force for good."
A campaign film highlights his justice fights and features words of support from Stephen Lawrence's mother Baroness Lawrence, who says he was "instrumental" in getting justice for her murdered son.
Sir Keir's work with the National Union of Mineworkers and on the McLibel case against McDonald's is also highlighted.
His Remain stance has been partly blamed by some Corbyn allies for the disastrous election performance.
Appealing to Mr Corbyn's base, however, Sir Keir urged the party not to lurch to the right and said the case for a "bold and radical" Labour government is as important as ever.
The human rights lawyer, who was made Queen's Counsel in 2002, served as head of the CPS and accepted a knighthood in 2014, and has struggled to shake-off perceptions of privilege.
He was named after Labour legend Keir Hardy and stressed his upbringing by his toolmaker father and nurse mother in London's Southwark when dismissing allegations he is too middle-class to speak to the party's historic heartlands.
His CV includes co-founding the renowned Doughty Street Chambers and advising the Policing Board to ensure the Police Service of Northern Ireland complied with human rights laws.
He entered Parliament as the MP for Holborn and St Pancras in 2015.
Meanwhile Wigan MP Ms Nandy began her campaign in her constituency on Saturday with a call for change from Mr Corbyn's approach.
"We need a different sort of leadership that helps to root us back in every community across the UK, turns us back into a real movement and real force, driven from the ground up so that we can win people's trust back," she said.
Birmingham Yardley MP Ms Phillips visited the Bury North constituency that fell from Labour to the Tories on December 12 to meet former supporters of the party.
Meanwhile, senior Labour MP David Lammy ruled himself out of the leadership contest, suggesting his anti-Brexit stance rendered him unsuitable to unite the party's "vociferous factions".