LONDON — To his critics, Jeremy Corbyn is little more than a socialist throwback to the 1970s.

But to the army of young, tech-savvy activists driving the U.K. Labour leader’s reelection campaign, Corbyn represents a break from the past rather than a return to it. His policies might be retro, but the methods are anything but.

This week the Labour leader’s campaign will launch a series of initiatives straight out of the Sanders playbook.

Corbyn's inner circle was on Tuesday putting the finishing touches to a “barnstormer” series of town hall meetings designed to dramatically ramp up the number of volunteers working on his campaign.

The move is a direct copy of Sanders’ influential barnstormer meeting circuit, organized on social media and attracting thousands of volunteers.

The concept is simple: Instead of recruiting a limited number of paid campaigners to organize door-knocking and handing out leaflets, cut out the middle men. Meetings are arranged and advertised online and volunteers who attend are quickly trained to become the ground operation themselves, taking on and organizing major aspects of the campaign.

The Corbyn campaign certainly cannot easily be pigeonholed into the old Trotskyite box — Paul Hilder

At one early barnstormer meeting in Brighton, hundreds of activists showed up to hear from Corbyn’s team. Following the event the campaign had an activist on the ground in every part of the city.

Following another meeting, in Bristol, the campaign developed a new smartphone app after asking for expert help from volunteers. All Corbyn’s team had to do was shout “who’s a techy here?”

Momentum gains momentum

In a second move taken straight from the U.S., the pro-Corbyn campaign group Momentum will this week launch a major crowdfunding drive with the money raised going straight to the Labour leader’s reelection bid rather than to the Labour Party itself. It will be the first major U.S.-style fundraising drive in the U.K. for leadership bid rather than a general election.

Local Momentum groups will “compete” to raise the most money in small donations from activists in a bid to blow Corbyn's rival Owen Smith out of the water.

In the first week of the recent attempted coup against Corbyn by Labour MPs, Momentum raised £11,000 a day, with the average donation just £7.30. It now hopes to ramp up the fundraising drive by using online crowdsourcing.

“The Corbyn campaign certainly cannot easily be pigeonholed into the old Trotskyite box,” said Paul Hilder, founder of the political crowdfunding website Crowdpac, who spent weeks embedded with the Sanders campaign earlier this year.

I was in Labour HQ and asked them to set up a Facebook livestream and they just looked blank at me — Labour staffer

Hilder is cited as an inspiration by some of the leading figures in Momentum for his work on political campaigning. He stood to be Labour general secretary in 2011 in a bid to overhaul the way the party operates and was involved in setting up the left-wing campaign website 38 Degrees. He was also a vice president of the giant U.S. petition platform change.org.

Hilder insists there is only one side of the Labour Party embracing the U.S.-style social media revolution in political campaigning championed by Sanders and before him by Barack Obama.

“We are seeing Momentum trying out some of the most innovative techniques pioneered by the Sanders movement,” Hilder said. In contrast, the Labour mainstream has become “professionally incompetent,” he said.

One senior Labour staffer summed up the difference. “I was in Labour HQ and asked them to set up a Facebook livestream and they just looked blank at me.”

James Schneider, senior Corbyn campaign organizer and Momentum activist, flew to the U.S. to study the Sanders campaign in April and describes Hilder as “a big influence” on his campaigning.

Schneider rejected claims that Corbyn's takeover of the Labour Party was a hard-left coup. “It’s not a takeover, it’s a revitalization and a modernization of the party,” he said, speaking outside Momentum’s offices in central London.

Campaign roadblocks

Corbyn’s leadership campaign has become increasingly reliant on Momentum following a technical ruling from Labour HQ that anyone in Corbyn’s office paid out of party funds cannot also work on the reelection bid.

That means a host of Corbyn’s closest aides have, effectively, been stopped from campaigning.

John McDonnell, the shadow chancellor, cannot be stopped from campaigning as an MP and is acting as chairman of Corbyn’s bid. But McDonnell’s press aide James Mills has been forced to resign in order to move over to the campaign. Jack Bond, who covered social media for Corbyn, has also left the leader’s office to help the reelection strategy.

Even relatively junior administrative aides have been affected by the ruling. Corbyn’s political secretary Laura Parker and diary secretary Ayse Veli have asked the party if they can liaise with the campaign for “security and logistical reasons” to keep track of Corbyn — but have yet to be given clearance.

“There are members of staff who are struggling to carry out their jobs because of the restrictions placed on them,” one well-placed source said.

Corbyn’s inner circle privately rail against the draconian nature of the ruling, which they believe is designed to hamper his chances of reelection. But it has allowed the Labour leader to forge an even sharper division between himself and his leadership rival Smith, who is backed by the vast majority of Labour MPs.

Corbyn’s allies believe Momentum's organization, which relies on volunteers and social media, gives them an advantage that Smith cannot match, no matter how much of Corbyn’s agenda he adopts.

'Not me, us'

Hilder said the Corbyn campaign was reminiscent of Sanders’ “not me, us” line during the Democratic primary race.

“If you step back and look at Sanders and Obama and many others, these demonstrate the remarkable energy that can be unleashed by the new 21st century movement politics."

“Sanders went from 3 percent in the polls to coming damn close to winning the Democratic presidential nomination and has changed the party in the process. Obama did something similar. There’s no doubt that with the right message and the right leadership, movement politics can reach and persuade many more voters than the traditional toolkit of speeches, voter ID, door knocking and billboards, that type of thing.”

To get people to go campaigning they have to trust the messenger. People trust the message is real — senior Corbyn campaign source

However, Hilder said he was not blind to Corbyn’s weaknesses. He admitted there was “no question the Corbyn movement faces huge obstacles if it wants to win a general election” and would only go as far as to say that Sanders’-style campaigning could help Labour "outperform expectations” rather than defeat the Tories.

But if Corbyn can’t win, what’s the point?

One senior Labour source was even skeptical of the idea that Corbyn’s campaign was that revolutionary.

“At the end of the day, both campaigns have phone banks, both campaigns have Facebook and both campaigns have a load of emails going out. What are they really doing that is different?"

“And how many voters are really up for grabs in this anyway? Jeremy has his army of supporters. Are they really going to be won over because of a few Facebook messages?"

“There are a bunch of middle-class graduates who are for Jeremy. The stuff on social media is just reinforcing what they already believe. Remember, a million people still read the ‘mainstream media’ every day.”

But the senior party figure, speaking on the basis of anonymity, admitted the feeling Corbyn’s supporters had of being involved helped engender a sense of enthusiasm.

Growing grassroots support

The figures are certainly impressive. Since Brexit, Momentum estimates 25,000 people have attended around 40 pro-Corbyn campaign rallies, even though the Labour leader has only been at a handful of them.

In contrast, during the entire 2015 Labour leadership election, 60,000 turned up to Corbyn campaign events. The numbers point to an increase in enthusiasm for his leadership over the past year.

At one rally in Leeds, a Momentum organizer filmed the queue of supporters waiting outside to hear Corbyn speak. The video was uploaded onto Facebook nine minutes later and seen 250,000 times within 15 minutes.

Pro-Corbyn channels on Facebook have racked up 18 million views, with 3.5 million shares, likes and comments.

Momentum itself is now a political force to be reckoned with, with 15,000 paid members and 160,000 supporters, making its membership larger than the Conservative Party.

Skeptics could be forgiven for asking why so many young graduates in the U.S. and U.K. are flocking to support white, male socialists who have passed retirement age.

One senior Corbyn campaign source said it boiled down to trust. “To get people to go campaigning they have to trust the messenger. People trust the message is real. You’ve got to remember, people are spending an enormous amount of time on this — they need to believe in it.”

But even among Corbyn’s closest supporters there is an acknowledgement that he might not be the one to get them into government. “It will be interesting to see what the next stage of this will be,” the senior Corbyn campaign source said.

Even if Corbyn fails to win over the wider public, his approach to campaigning may outlast his leadership of his party.