Correction Jul. 26: This article originally incorrectly identified Marcus Barnett as Marcus Bennett.

England, United Kingdom - Angela Eagle's Facebook call to action on the day she announced her leadership bid for Britain's opposition Labour party could serve as a cautionary tale in the age of internet trolling and hashtag warfare.

The politician posted a graphic calling on her supporters to join her campaign to replace the Labour leader, Jeremy Corbyn, who faces a leadership challenge after his MPs successfully passed a no-confidence motion against him.

"I'm with Angela," the graphic read.

What followed was a torrent of comments - nearly 50,000 in total - the overwhelming majority in the form of hashtags backing Corbyn, shutting out from view any that may have been supportive of Eagle.

A year after Corbyn took the helm of the UK's largest political party, the pro-Corbyn Momentum organisation - which grew from his election campaign - has established itself as one of the biggest pressure blocs within Labour and British politics as a whole.

As of the start of July, Momentum boasted 12,000 signed-up members and drew in £11,000 ($14,600) a day in donations. The figures belie a bigger and more influential presence on social media, where supporters are regularly able to get pro-Corbyn hashtags trending on Twitter and, as Eagle learned, draw attention away from his opponents' online efforts.

Such success has not come without controversy and Corbyn's supporters have been accused of bullying and intimidating opponents. Senior Labour figures, including deputy leader Tom Watson, have warned of the "entryist" threat Momentum allegedly poses, while former minister Ben Bradshaw has called supporters "thugs".

Momentum has rejected such behaviour and called on its supporters not to abuse its opponents. But activists Al Jazeera spoke to said there were more cynical motives at play and that the movement was being misrepresented by an "established order" desperate to fend off any threats it faces.

"I don't think they really think we're thugs but they're trying to use the media contacts that they have to put down a movement that is essentially an existential threat to their kind of politics," said Deej Johnson, a Labour party and Momentum campaigner who sits on the latter's youth committee.

At a coffee shop off Market Street in Manchester city centre, Johnson - from the nearby suburb of Oldham - assertively detailed his Labour party pedigree; his parents and grandparents were lifelong Labour supporters and his great grandparents were founding members of the local party chapter.

Johnson initially joined Labour in his early teens but left in disgust at the Iraq War and the party's apparent rightward tilt under Tony Blair. Corbyn's ascendancy in 2015 - from backbench MP to eventual leader - drew him back into the party fold.

"I was feeling good about this guy Jeremy Corbyn because of his involvement against the war and his background in the anti-apartheid movement."

According to Johnson, Corbyn was a "sensible socialist", offering what had been missing in mainstream politics for two decades - a voice for ordinary Britons.

"He actually cares about working-class people."

Winning back the heartlands

A theme in internal debates within Labour has been its declining appeal among its traditional white working-class vote. In the 2015 general election the party saw a dramatic loss of support in its northern heartlands to the anti-immigration UKIP party.

Some Labour politicians have tried to address such losses by including immigration reforms in the party's platform. The party was mocked for the release of an "immigration controls" coffee mug in the run-up to the 2015 vote.

Momentum activists say the party will not win back supporters by repeating right-wing talking points but by concentrating on the day-to-day struggles of working people.

Railway worker Marcus Barnett described how many of Labour's traditional supporters felt abandoned by the party.

"In the part of Lancashire where I'm from, you can stick a red rosette on a donkey and they'll still elect the Labour candidate," Barnett - who joined Labour in 2010 - said, referring to the party's colours.

"But [before Corbyn] there was a really clear widespread disaffection and a sense of grotesque disappointment that Labour hadn't achieved anything."

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The 25-year-old - a close friend of Johnson's - said the party had squandered the landslide mandate it received in the 1997 general election by going to war in Iraq and adopting a corporation-friendly platform at the expense of working people.

"There was a wave of enthusiasm and a parliamentary sweep but they [Labour] did absolutely nothing ... you got yuppy flats, private business in the NHS, and Iraq.

"They drove a good few million voters away from Labour and the disaffection has been shown in the rise of UKIP and the SNP in Scotland."

The change of direction under Corbyn was a statement of intent from Labour's long-ignored base, according to Barnett. The native of the Lancashire mill town of Chorley conceded that Corbyn had not managed to fully communicate his policies to the masses - but said that would soon change.

"People like Jeremy Corbyn are really unambiguous in their message and straight-talking in their politics, and that really appeals to people."

Internal disputes

The incumbent Labour leader's rise came amid the biggest cuts to public spending [PDF] since the Second World War. In the years since the Conservative election victory in 2010, government has scaled back on benefit spending, contributing to a rise in extreme poverty in the country.

The activists Al Jazeera spoke to were near-unanimous in their feeling that those poor to begin with were being hit hardest by austerity measures. But despite five years of cuts, Labour lost more seats in 2015 than it had after the 2010 vote.

David White, a retired solicitor who joined the party in 1970 and served as a councillor in the London suburb of Croydon, said Corbyn could connect with voters who would otherwise be indifferent to politicians.

"Austerity has had a devastating effect on a large number of people, particularly the unemployed, single parents, the disabled and those on low wages.

"People feel there's an elite running society … with the election of Corbyn there was a hope of more inclusion, more honesty and more democracy."

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For White, as with other Momentum activists, there was a feeling that Corbyn's ability to relay his anti-austerity message was being hindered by some in his own party.

"Even if some MPs didn't agree with Corbyn's policies, they should have realised the value of a leader who can enthuse thousands to join the party. They should have helped Jeremy, but they did the reverse."

New members

Despite frosty relations with most of his parliamentary colleagues, since winning last year's leadership vote Corbyn has drawn tens of thousands of new members.

Labour opponents of the embattled leader have warned that there is an entryist current trying to shift the party to the far-left, but newer members Al Jazeera spoke to said they were attracted by Corbyn's offering of a clearly distinct platform to the ruling Conservative party.

"[Corbyn] is building a real opposition to the Tory [Conservative] government rather than going down the already-failed route of trying to be 'Tory-lite'," said charity worker and Labour member Alia al-Ghussain, citing an "appetite" among Britons for something different.

"Since Corbyn became leader, I feel like [Labour] has the potential to become a party that can bring a more positive kind of politics to the UK."

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Similarly, recent graduate Diana al-Ghoul said she joined Labour "purely for Corbyn", adding that she objected to media representations of his backers as idealists.

"Many media outlets are portraying his supporters to be naive and somewhat radical … this is an unfair generalisation," she said, blaming the legacy of former Prime Minister Tony Blair for the fact that she had not joined the party earlier.

Loss of support

Despite the surge in new members signing up to Labour because of Corbyn, there are some who welcomed his election last year who feel that he has failed to deliver a credible alternative to Conservative rule.

Lancaster University lecturer Ketan Alder told Al Jazeera that as a fledgling academic he was initially "elated" with Corbyn's election but had lost faith in the Labour leader's ability to articulate his vision.

"There's lots of honourable and credible stuff about him, like his anti-austerity stance, but at the same time I think his period has been pretty disappointing.

"He hasn't been able to push through media representations of him, partly because the media team around him don't seem to be up to the job, which is sad."

Alder said there was a big step up between building a successful grassroots support movement and turning it into a viable political force.

"The confidence that he's being given by the Momentum activists that 'we've signed up 200,000 and 300,000 members' doesn't equate to electoral gains."

For Alder, Corbyn's failure to tackle anti-immigrant rhetoric and win over working-class voters in the recent referendum over Britain's continued membership of the EU was indicative of how the Labour leader would fare in any future general election.

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The threat of a split

Corbyn looks set to come out on top in August's leadership vote - where he will only be up against Owen Smith since Angela Eagle pulled out of the race - and despite reports that some Labour MPs are planning to break away from the party, the activists Al Jazeera spoke to said they would work towards maintaining the party's "broad church".

Back at the backstreet café in Manchester, Johnson and Barnett were keen to emphasise that success was measured not only in elections won but also by normalising the concerns of working-class people in political discourse.

Both activists were confident about Corbyn's electability but for the pair a greater struggle lay in opening up Labour to more voices like his.

"I'm not a member of the Jeremy Corbyn cult," Johnson said.

"My vision is to create a party where there are a lot of people with these ideals - so it shouldn't rely on one figurehead."