Barcelona presidential candidate Joan Laporta led the criticism after the club's managing committee agreed a deal to sign Arda Turan from Atletico Madrid before the election takes place.
Barca will not have a president until the election on July 18, but the club announced on Monday that an agreement had been reached with Atletico to acquire Turan for an initial fee of €34 million, with the management committee saying in a statement: "The decision could not be put off any longer."
They said they had inserted a clause in the deal giving the club the right to re-sell the player back to Atletico until July 20, effectively allowing any new president to annul the deal.
Josep Maria Bartomeu, who has stepped down as president ahead of his bid for re-election, said earlier this month that coach Luis Enrique had requested the player and that his board had left the matter in "an advanced state" before stepping down.
However, Laporta, who had held the presidency between 2003 and 2010, had previously told Cadena SER that Barca had only made a move for Turan to "cover up the ridiculousness" of their failure to sign Paul Pogba from Juventus and said no transfer business should be conducted before July 19.
He has now suggested that Bartomeu -- who secured a series of PR coups before stepping down, including new contracts for Luis Enrique and Dani Alves -- orchestrated the Turan deal in a further attempt to sway voters.
"It's something improper," he told El Mundo Deportivo. "If he thought they had to sign Arda, he should have done it before resigning.
"It's out of order, this sense of urgency ... and the only explanation is that it favours the candidature of Bartomeu."
He referred to the controversy of the Neymar deal, agreed when Bartomeu was vice-president, adding: "They already showed a lack of transparency when signing Neymar and I believe that for the management committee to play this game is insane."
Another presidential hopeful, Agusti Benedito, agreed that the Turan deal should not have been sanctioned before the election.
Benedito told El Mundo Deportivo: "I already told [president of the management committee] Ramon Adell on Saturday that it goes against the spirit and against the electoral process that the management takes this type of financial decision considering that, in a few days' time, we will have a new president, who will have full legitimacy."
If elected, Benedito suggested he is likely to exercise the clause included in Turan's transfer that allows the incoming president to reverse the operation.
"We don't agree with Arda's signing and would rather have another player with a different profile," Benedito said.
Toni Freixa, another of the five candidates for the presidency, also said the management committee made its move too quickly.
"I respect the work done by the committee," he said. "However, if there is the possibility to sign this player or another, there is time to do so until the Aug. 31."
Bartomeu -- who had warned last month that Barca could not afford to allow the likes of Real Madrid to seize an advantage in the transfer market -- has maintained that the deal is to the benefit of the club.
"I thank the management committee because, with this decision, the club has taken a step forward and the club wins," Bartomeu told Marca. "I'm very happy that the deal has been completed and this is really exciting for the fans."
Bartomeu had also overseen the arrival of Aleix Vidal -- whom he said was Luis Enrique's other primary transfer request -- before stepping down as president.
However, neither Vidal nor Turan will be able to play in official games for Barca until January 2016 as the result of a FIFA transfer ban, which was imposed after the club breached rules regarding the signing of under-age players between 2009 and 2013.