The deadline to file challenges to independent and third-party candidates is Friday, Aug. 8.
On Monday, Nader and his 2004 running mate, Peter Miguel Camejo, said the ballot challenge was orchestrated by Democratic lawmakers and House aides as part of a conspiracy to illegally spend public money for political purposes.
In the 2004 challenge, nearly two-thirds of Nader's signatures were declared invalid following a review that involved 11 Commonwealth Court judges.