
Pheu Thai Ayutthaya MP Withaya Buranasiri earlier floated the idea of the appointment.
Sodsri said that although electoral law did not specifically forbid banned politicians to be party advisors, Phue Thai should fight shy of electoral complaints.
"If the EC rules that the appointment adversely affects the country's stability and violates electoral law, the Constitution Court may dissolve the party,'' she said.
She said she personally felt that the proposal was inappropriate. Phuea Pandin earlier sought an EC ruling on the same issue, and the EC said it was inappropriate, whereupon the party acquiesced in the decision.
Sodsri's comment came under attack by Pheu Thai Chiang Mai MP Surapong Tovichakchaikul, who called the commissioner discriminatory.
Surapong said the party would not scrap the plan to appoint Thaksin as party advisor because party legal specialists had scrutinised electoral law and believed the appointment was legal.
He hit back at Sodsri, questioning why she did not take action in the cases of Newin Chidchob, Suriya Jungrungreangkit and Somsak Thepsuthin, banned former executives of the Thai Rak Thai Party who took part in the founding of the Phum Jai Thai Party.
He also questioned why the EC had not taken action against Newin for publicly taking part in politics by backing the Democrat Party's bid to form a government, bringing the Friends of Newin group of MPs under his control over to the Democrat camp.
Barred Thai Rak Thai Party executive Adisorn Piengket said the red-shirts would retaliate if the party was dissolved for a third time.