Allison Patton, who until this week was a constituency association president in Surrey, made the challenge after she received a letter from party president Al Siebring kicking her out of the Conservatives.
Patton was among 15 party members who were sent letters of reprimand or expulsion for publicly calling on Cummins to resign.
Patton, who sent reporters a photo of her holding a framed copy of her expulsion letter, issued a statement claiming she doesn't know why she's been labelled a dissident and expelled.
"In fact, no one in the party has spoken to us on this matter now or before," she wrote.
"It was only after that (dissident) label was applied to us and we were threatened with expulsion that we asked for Mr. Cummins' resignation."
Patton said she wants "a truth and reconciliation committee" to clear up the confusion, or, failing that, a debate that would see Cummins square off against both Patton and Ariane Eckardt, another of the so-called dissidents.
Patton asked that one of those two things happen within the next seven days.
On Monday, the party's president announced he had mailed out a series of letters censuring or expelling members who've been calling on Cummins to resign, as well as the creation of a "unity committee."
Patton included the letter she received from the party's president, which alleges Patton broke the party's bylaws by publicly calling for Cummins to resign after the issue had already been settled by a leadership vote.
The challenge comes after months of infighting that were fuelled by the party's disappointing performance in two spring byelections.
That infighting boiled over last month as opponents threatened Cummins' leadership in a vote at the party's annual general meeting, but Cummins survived with a vote of 70.1 per cent.
That leadership vote did little to calm Cummins's opponents within his own party.
Immediately, the party lost its only sitting member of the legislature, John van Dongen, who earlier crossed the floor to the Conservatives from the Liberals. He now sits as an independent.
After the leadership vote, Cummins told dissidents to get in line with his leadership or leave the party.
That prompted several constituency presidents to hold their own news conference, warning that contributions to the party would dry up if Cummins didn't quit.
It was that news conference that, in turn, led to the censure and expulsion letters.
The party currently has no members in the legislature.
The next provincial election is scheduled for May of next year.