Malaysia's ruling coalition Barisan Nasional (BN) has kept a stranglehold on rural Sarawak constituencies for the past 47 years by leveraging on development projects and the promise of more progress.

But controversial mega projects which threaten to force tens of thousands out of their ancestral homes have incensed some native communities, which accuse the state government of ignoring their customary rights.

The proposed 389-sq-km Baram Dam in the Telang Usan constituency is one such development, and the seat is ripe for the opposition to take. BN won the seat by a mere 845 votes in the last state polls in 2011.

Some 1.14 million eligible Sarawakians will vote on Saturday after a 12-day campaign period.

In the past three years, the opposition has capitalised on the anger of some 20,000 indigenous people living in 26 villages that would be submerged by the Baram Dam.

And Parti Keadilan Rakyat's (PKR's) candidate Roland Engan is confident that the opposition will gain votes as its people have been campaigning against the dam.

"The people witnessed our team on the ground for so long, they want consistency and somebody who is vocal and fights for their cause," Mr Roland told The Straits Times at his operations centre in Miri, the state's second largest city.

However, the advantage that PKR gained may have been diminished by the cancellation of the project, which Chief Minister Adenan Satem announced last week.

"The fact is there will be no Baram Dam as long as I am Chief Minister," Tan Sri Adenan told reporters.

Telang Usan residents who spoke to The Straits Times expressed relief at the project's cancellation but some were sceptical about Mr Adenan keeping his promise. They were worried that the project may be revived in the future.

"I'm afraid later, if BN wins, the project will go ahead. That is what we do not want, we are worried," 39-year-old farmer Mariam Jew told The Straits Times at her longhouse in Long Apu village.

Mr Peter Kallang, chairman of the non-governmental organisation Save Rivers who led the charge against the dam, wants to see the cancellation put in black and white.

"If Adenan is no longer around, will this policy be carried forward (by his successor) or not?" asked Mr Peter in Tanjung Tepalit, one of the villages that would have been affected.

BN's Telang Usan candidate Dennis Ngau was quick to say that the state government had made the cancellation official by de-gazetting the land earmarked for the project.

Analysts say the opposition might still have a chance at the polls because of longstanding "hot issues" such as the denial of native customary rights (NCR) land and a lack of basic infrastructure like roads, electricity and clean water.

Political analyst Awang Azman Awang Pawi sees a 50-50 battle for Telang Usan.

"It depends (on) whether there will be a dirty campaign involving money politics," he said.

He also said the politics of personality could cost BN some rural seats, namely Beting Maro, Sebuyau and Pakan, where the people are not against BN or Mr Adenan but dislike the chosen BN candidates.

While the opposition is keen to defend the urban seats it won in the last election, it must also capture some rural seats if it wants to loosen BN's grip on the state and be a more effective opposition.

Mr Lim Kit Siang, veteran leader of the Chinese-based Democratic Action Party, has repeatedly called on rural voters to help "create miracles" and deny Sarawak BN a two-thirds majority by voting at least 28 opposition candidates into the state assembly.

Associate professor Neilson Ilan Mersat of Universiti Malaysia Sarawak said the natives may vote for the opposition over concerns that the government would not defend their NCR land rights, especially against timber companies.

Prime Minister Najib Razak has told the people in rural Lawas that the federal government had contributed RM100 million (S$34 million) towards a survey of NCR land in Sarawak and Sabah. But the opposition argues that "throwing money at this problem" would not solve it as the state government was surveying only farmed land and not the "pemakai menoa" (territorial domain) and "pulau galau" (forest reserves).

Sarawak PKR chief Baru Bian said in a press statement that if the opposition coalition Pakatan Harapan were to form the state government, it would amend the Land Code to include the pemakai menoa and pulau galau as NCR land. "To get more attention from the government for neglected areas, Sarawakians should vote for PKR," he added.