James Clarke, one of three “principals” at the head of Renew, said the fact the party planned to field candidates across the country at the next general election would put pressure on sitting MPs to reconsider EU withdrawal.
Launching the new centrist party in London, Mr Clarke said: “Some of the anti-Brexit pressure groups and movements are very, very much focused on asking people to pressure their local MP to have a second thought on Brexit.
“What we are is almost the more military arm of that movement, whereas we are actually standing candidates in seats to threaten those MPs that are not changing their minds, or are not standing up for the views of their constituents.”
Co-leader Sandra Khadhouri, a former UN and Nato worker, said the Brexit referendum had left Britain a conflict zone.
“As I finished working in Georgia for Nato last year I looked at which conflict zone to go to next and I decided it had to be Britain.”
Ms Khadhouri said “extremes are prevailing” in the wake of the referendum vote.
“Millions in this country feel politically homeless right now and abandoned. Brexiteers and Remainers, old and young, north and south. Many are disappointed with the false promise of Brexit.
“It is leaving us poorer, damaging us in many ways, and distracting us from addressing real problems of inequality and division.
“Existing parties are failing to protect people’s interests due to personal ambition and tribal loyalties. Extremes are prevailing.”
Ms Khadhouri said Renew’s message to Brexit voters now having doubts was “it’s not your fault”.