ANKARA (AFP) - Turkey's prime minister is set for a third straight term in power in June 12 polls but doubts linger on whether he could win a strong enough majority for a much-craved constitutional overhaul. Pollsters predict Recep Tayyip Erdogan's Justice and Development Party (AKP) will easily come first, with about 45 percent of the vote, enough to form a third one-party government since 2002. "Because of political polarization in the country, it is already obvious who will vote for whom. The election campaigns are ineffectual," Bekir Agirdir, the director of the KONDA research company, told AFP. Some polling companies say the AKP may even hit the 50-percent mark, drawing mainly on a booming economy, improved public services and special care for the poor. The main opposition Republican People's Party is said to stand a chance to increase its vote by about a half to some 30 percent, posing its strongest challenge yet to the AKP at a time when Erdogan is under mounting fire for growing authoritarianism. The NAP is still expected to overcome the 10-percent threshold and enter parliament, along with Kurdish-backed independent candidates.