Launching a tirade against Democratic presidential candidate John Kerry, Nader on Friday also denied charges that he was heavily supported by Republicans.
"I say to Senator John Kerry, call off your dogs," Nader said in Los Angeles. He accused Kerry supporters of "harassing, obstructing and impeding" his efforts to get on the ballot in all 50 states.
"Stop encouraging these dirty tricks or you will be held responsible," he added.
He said the dirty tricks included Democratic activists "directly harassing" his signature-gatherers in West Virginia and filing legal challenges to his candidacy in Arizona that he could not afford to fight in court.
Nader also disputed accusations that he had become a tool of the Republican party.
Asking the Democrats to stop "freaking out" over his candidacy, he denied that his name on the 2000 ballot denied Al Gore a chance at the presidency.
He pointed out that "slightly under 10% of contributions to his campaign came from Republicans, virtually all from individuals".