Jon Lansman, who founded the leftist movement, said a Labour Government would make transformations so “significant” it will face the resistance from global corporations and will even see a mass selling off of the pound sending its value plummeting.
Speaking to BBC Radio 4 programme Long March of Corbyn’s Labour, which will be broadcasted on Monday, he said: “We want to make a significant transformation.
“We want decisions which affect jobs and livelihoods democratised.
“The global corporations will resist.
“Other governments have faced challenges like runs on the pound.
“And we may face similar things. I hope we don’t.
“The people who are opposed to what we want to do have one thing in their favour – money.
“We have people. We need the power of people to overcome the power of money.”
But such plans are set to open an even wider rift within the party.
In the same BBC programme, shadow communities secretary and joint election co-ordinator Andrew Gwynne confessed he has had “sleepless nights” amid worries local councils could not be able to sustain some of “the big ticket” items in Labour’s manifesto.
Among the promises made in the party’s programme, there is the pledge to deliver a million more homes over a decade.
Mr Gwynne also warned that a Labour government disappointing its new members could “fall at the first hurdle”.
He said: ”Some things are going to take time and we need to communicate that now in opposition.
“If we come to power on the back of massive optimism, a new way of doing things, and we fall at the first hurdle then it will be very difficult to recover.
“We need a clear plan.”
An alarming prospect similar to the one set out by the Momentum leader was also raised by Shadow Chancellor John McDonnell at a fringe meeting during last year’s Labour conference.
Explaining the party has “got a scenario plan for that”, he said: “What if there is a run on the pound?
“What happens if there is this concept of capital flight?
“I don’t think there will be, but you never know.
“People want to know we are ready and they want to know we have got a response to everything that could happen.
“Because if we can demonstrate that, that will calm things down.”