Opposition pact Pakatan Harapan (PH) has claimed victory in Kedah, the home state of former prime minister Mahathir Mohamad and a key battleground state in Malaysia's election yesterday.

"Unofficially, we have captured... Penang, Selangor, Melaka, Negeri Sembilan and Johor and Kedah. So, that is six," PH leader Tun Dr Mahathir said yesterday.

Kedah voters changed state governments twice in the past, in 2008 handing power from the Barisan Nasional (BN) ruling coalition to the opposition Pakatan Rakyat, led in the state by Parti Islam SeMalaysia. They returned the state to BN in the next election in 2013, when BN won 10 of 15 parliamentary seats and 21 of 36 state seats.

As at press time, the Election Commission (EC) had not confirmed state seat results for Kedah. According to PH, it won 20 of the 36 seats, granting it control of the state assembly.

Dr Mahathir, 92, led the PH charge in his home state Kedah, winning his parliamentary seat in Langkawi, the island he helped transform into a tourist destination. He was bolstered by the presence of his son - former Kedah menteri besar Mukhriz Mahathir - who ran in both the Jerlun parliamentary seat and the state seat in Jitra, and was confirmed by the EC to have won Jitra.

For this election, analysts have said the "Mahathir factor" could trigger a Malay tsunami, with rural Malay voters abandoning BN to vote for the opposition.

On voter support for the Mahathir family, ISEAS - Yusof Ishak Institute visiting research fellow Serina Rahman said: "It is their faith in the Mahathir family that they can fix what is wrong and guide the opposition to improve the situation in the country - at least to bring it to how it was during their regime.

"It also means that Kedahans are not swayed by the fear tactics used against the opposition and are more aware of political conditions and national issues."

Scores of voters, including women with babies and elderly men in wheelchairs, were seen queuing to vote in their constituencies yesterday. National issues - mainly rising living costs and the 6 per cent goods and services tax - remain a top concern for Kedahans. They said the return of Dr Mahathir gives them that hope that their economic woes will be addressed.

"We work very hard, but we still can't make ends meet. We only ask for leaders who will take care of us. It is time for a change," said 60-year-old farmer Fazil Abdul Rahim from Yan district.