The (Montreal) Gazette reported the members took the action at the party's national council meeting in Montreal despite its opening the door to a potential defeat that could end their endeavors once and for all.
The party also voted overwhelmingly in support of a resolution to prevent members of the province's National Assembly from switching parties.
The newspaper said the vote was narrower on proposals for a new elected upper house to the assembly and to lower the voting age to 16 from 18, but both passed.
"The pot is beginning to boil again," The Globe and Mail quoted Alain Dion, a delegate from Rimouski, as saying. "With the possibility of holding a citizen-led referendum we are sending a clear signal to all sovereigntists ... that there is a means now to get the process going again."
Party leader Pauline Marois, who had opposed citizen-led referendums, acquiesced to the wishes of rank-and-file members, the Toronto newspaper said.
"We know what the remedy is. We have to liberate the Quebec economy," she said. "... Liberate Quebeckers from the oil industry and liberate Quebec from Canada."