Erdogan's two-month-old offensive against the PKK, which has responded with a ferocity not seen since the 1990s, is viewed with suspicion by his critics.
They accuse him of using a suicide bombing in the southeastern town of Suruc that was blamed on Isis (Islamic State) jihadists as a pretext for reigniting the three-decade-long conflict for electoral gain.
Erdogan has tarred the PKK and Isis with the same brush of extremism, but devoted much more firepower to airstrikes on PKK bases along Turkey's border with Iraq than to air raids against the Kurds' jihadist foes in Syria.
On Friday, an "anti-terrorism" rally in the capital, Ankara, drew more than 10,000 people.
While some demonstrators in Ankara were circumspect about Erdogan's motives, those in Istanbul expressed fervent support for him and his Islamic-rooted Justice and Development Party (AKP).
The AKP is looking to the forthcoming election to reverse the losses it sustained in an inconclusive poll in June, which stripped it of its governing majority, forcing it into coalition talks that ended in failure.
The big winner of that vote was the pro-Kurdish People's Democratic Party (HDP), which won seats in Parliament for the first time.
A combative Erdogan, who had been counting on the AKP winning a large majority in order to amend the constitution to boost his powers, laid into the HDP, without expressly naming it.
Alluding to the Government's accusation that the HDP is a front for the PKK - allegations the party vehemently denies - he urged voters to vote AKP "so that peace returns to Turkey".
Speaking before him, Prime Minister Ahmet Davutoglu made overtures to the country's 20-million-strong Kurdish minority.
"Turks and Kurds are brothers, there is no difference, those who want to divide us will not succeed."
While the timing of Erdogan's offensive against the PKK has raised eyebrows, the rebels' bloody response has caused widespread anger.
More than 120 soldiers and police have been killed in attacks since the ceasefire was broken, according to pro-government media. The Government claims to have killed over 1000 rebels.
- AFP