The grassroots group was set up in 2015 on the back of Corbynmania to help secure the Islington North MP’s victory in the leadership contest. The socialist campaign movement was highly influential over the Labour Party during Mr Corbyn’s four-year tenure in the top job.
Following Sir Keir Starmer’s election victory in April, Momentum – which urged its members to back Rebecca Long-Bailey for leader – vowed to “hold Keir to account and make sure he keeps his promises”.
Demanding he stick with Mr Corbyn’s far-left policies, they added: “His mandate is to build on Jeremy’s transformative vision, and this means appointing a broad shadow cabinet who believe in the policies and will work with members to make them a reality.”
But, yesterday allies of Mr Corbyn who oppose Sir Keir’s leadership suffered a severe setback when they lost Momentum’s internal elections.
An internal faction called Momentum Renewal, backed by hard-left MPs including Richard Burgon, Ian Lavery and Jon Trickett, was emphatically defeated.
Not a single seat elected by members to the campaign group’s governing body was won by the faction.
All 20 member representative seats were won by the Forward Momentum, a rival faction which is more willing to support Sir Keir as leader.
One supporter of Forward Momentum said: “There’s two kinds of left in the Starmer era — one that wants to critically engage with what he’s trying to do and another that just wants to carp.”
Drawing a line under the organisation’s previously uncompromising support for My Corbyn’s hard-left policies Gaya Sriskanthan, one of the newly elected representatives, said the results represented “a fresh start and a new direction” for Momentum.
Sir Keir Starmer has been Labour leader since his election victory was confirmed on April 4.
In less than four months he has wasted no time in wrestling control of the Labour Party, quickly eradicating Mr Corbyn’s legacy.
In a reshuffle of the Shadow Cabinet the week after his election victory, he sent all of his predecessor’s closest allies to the backbenches.
Only his former leadership rival, Ms Long-Bailey, survived the cull but she too has since been dismissed.
Sir Keir sacked the Salford MP as Shadow Education Secretary last week after she shared a newspaper article that included an anti-Semitic conspiracy theory.
The Labour leader has also taken about replacing senior members of staff appointed to the Labour Party by Mr Corbyn.
In another clear sign of a break from the past, Seumas Milne, the former director communications and special adviser to Mr Corbyn, also left his senior role in the party.
Sir Keir vowed “change” in the party when he won the leadership election in April, saying the party had a “mountain to climb” to be taken seriously again.
In his victory speech, he said: “We’ve just lost four elections in a row. We’re failing in our historic purpose.
“Be in no doubt I understand the scale of the task, the gravity of the position that we’re in.
“We’ve got a mountain to climb. But we will climb it, and I will do my utmost to reconnect us across the country, to re-engage with our communities and voters, to establish a coalition across our towns and our cities and our regions with all creeds and communities to speak for the whole of the country.