Wigan MP Lisa Nandy has announced she is joining the race to replace Jeremy Corbyn as Labour leader.
In a letter to the Wigan Post, she said she wanted to “bring Labour home” to voters that have abandoned the party in its traditional strongholds.
She is the fourth contender to officially declare she is standing, alongside Jess Phillips, Emily Thornberry and Clive Lewis.
Mr Corbyn is standing down following the party’s heavy election defeat.
Shadow Brexit secretary Sir Keir Starmer and shadow business secretary Rebecca Long-Bailey are among those also considering a leadership bid.
A timetable for the leadership election – and any rule changes – is set to be decided by the party’s ruling National Executive Committee (NEC) on Monday.
In her letter, Ms Nandy said Labour would never win another general election without support in former “heartland” seats.
She said a future Labour government should give “power and resources” to people in “every town, city, region and nation in the UK”.
“We must leave behind the paternalism of the past and give people the ability to deliver change for themselves,” she wrote.
She said Labour needed a leader who is “proud to be from those communities” and said she agreed with the perception that many political leaders were “unable or unwilling” to understand places like Wigan.
“I am determined to defeat Boris Johnson in order to lead the compassionate, radical, dynamic government that I firmly believe you want and deserve.”
Lisa Nandy chose an unconventional way to launch her campaign – an open letter to constituents in her local paper.
In a challenge to London-based candidates such as Emily Thornberry and Keir Starmer, who will declare his candidacy soon, Ms Nandy argued that the next Labour leader should come from a community like hers.
She said she agreed with the perception that many political leaders were “unable or unwilling” to understand places such as Wigan – and that her party must elect, in her words, someone who has “skin in the game”.
She also pledged not to indulge in faction-fighting. In her pitch to succeed Mr Corbyn, she said the response to anti-Semitism had been “woeful”.
She promised to challenge Boris Johnson with “passion and precision” and argued that the best way for Labour to win back lost voters was by being “brave and bold” rather than “trying to look all ways”.
Ms Nandy has represented the safe Labour constituency of Wigan since entering Parliament after the 2010 general election.
She served as shadow energy secretary during the first year of Mr Corbyn’s leadership, but was among a clutch of shadow ministers to quit their posts in 2016 following the Brexit referendum.
She advocated remaining in the EU during the referendum campaign, but voted for the PM’s Brexit deal in October and has argued the party’s pledge to hold another referendum after renegotiating the deal alienated voters in Leave-supporting areas.
She has been urging her party to concentrate on winning support in smaller towns, and suggested it should move its headquarters outside London.
Ms Nandy’s announcement comes after Jess Phillips joined the leadership race on Friday, stating that “something has to change” and “more honesty” in politics was required.
Ms Phillips, a vocal critic of Mr Corbyn’s leadership, acknowledged the campaign “won’t necessarily be an easy fight” for her, but said she thought Labour members were “ready to try something different”.
The Birmingham Yardley MP added that Labour needed a leader who would “truly speak truth to power” and be able to “take on” Mr Johnson.
There will also be an election for a new deputy leader, with shadow justice secretary Richard Burgon, shadow equalities minister Dawn Butler and shadow Europe minister Khalid Mahmood confirming they intend to run.
Shadow education secretary Angela Rayner has also received the backing of Ms Long-Bailey for the deputy post.
Under current rules, would-be candidates for both the leader and deputy leader roles must first be nominated by more than 20 MPs.
They must also secure nominations from at least 5% of Labour’s constituency parties or three affiliated bodies – two of which must be trade unions.