The poll, conducted with 1,582 respondents by Metropoll Research Company, showed support to the ruling AKP fell to 35 percent in October, Vatan daily reported.
The AKP had 51 percent of voter support in a September poll conducted by the same company.
The corruption claims surrounding the AKP and the economic crisis are believed to have undermined support to the ruling party.
The percentage of undecided voters stands at 13.8 percent, the poll also showed.
According to the poll, support to the main oppostion Republican People's Party (CHP) rose six points to 15.5, while support to the Nationalist Movement Party (MHP) was two points up to 8.6 percent.
The poll also showed that 51.4 percent of the Turkish people think that the army had fault or neglect about the losses in the PKK attack on a military post in the southeastern region of Aktutun, in which 17 Turkish soldiers were killed. A total of 32.7 think the army has neither fault nor neglect.
Sixty-five percent of respondents did not approve of Turkish Prime Minister Tayyip Erdogan's call for a boycott of Dogan Media Group's newspapers, according to the poll. Forty-four percent of AKP voters also did not back his call.