The men were arrested in July in central England after a search of an impounded vehicle found hidden guns, a nail bomb and other weapons, prompting police to trace and arrest the driver, the passenger and the other suspects.
Jewel Uddin, Omar Mohammed Khan, Mohammed Hasseen, Anzal Hussain, Mohammed Saud and Zohaib Ahmed — all from Birmingham in central England — were charged with preparing an act of terrorism.
They pleaded guilty by video link Tuesday at London's Woolwich Crown Court, and were told by Judge Nicholas Hilliard that "there is no doubt" they will face "significant custody" when they are sentenced on June 6.
Prosecutors said the men were preparing to attack a June 30 march of the EDL in Dewsbury, northern England. But the men, traveling in two cars, arrived after the rally had ended.
Uddin — who was already under surveillance by British authorities — tried to drive back towards Birmingham with Khan, but they were stopped by a traffic officer and their silver Renault Laguna was seized because it was not insured.
The car was impounded, and counterterrorism officers were called in after a search of the vehicle uncovered sawed-off shotguns, swords, knives, a nail bomb and a partially assembled pipe bomb. There was also a note, filled with angry comments about enemies of Islam.
Marcus Beale, assistant chief constable with West Midlands Police, said the men were "clearly a radicalized group" with dangerous motives.
"Their intent was to recklessly cause mayhem and probably mass injuries," Beale said.
Beale defended the police response in light of revelations Uddin was already under surveillance in relation to another terrorist plot, saying counterterrorism units were "doing what was right and proportionate" at the time.
"We didn't fail to join the dots," he said.
The English Defense League claims to be a peaceful opponent of radical Islam.
Cassandra Vinograd can be reached at http://twitter.com/CassVinograd