The unpopular goods and services tax (GST), soaring living costs, the 1MDB financial scandal and the epic battle between Prime Minister Najib Razak and Mahathir Mohamad. Ask any Malaysian, and chances are they will cite these four issues as the themes dominating the country’s general election due on Wednesday.

But the past week of official campaigning has sprung a few surprises and could well provide new twists. Here is a closer look at five factors that have surfaced as potential wild cards that could shape the decisions of nearly 15 million voters when they head to the polls.

ISLAMIST PAS: SPOILER OR KINGMAKER?

The Islamist party Parti Islam se-Malaysia (Pan-Malaysian Islamic Party, or PAS) was a stalwart in the opposition alliance forged by jailed opposition leader Anwar Ibrahim until 2015, when it was ejected because of its position on expanding sharia law in the country.

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It won 21 seats in the 2013 election, but seven of its parliamentarians later defected to join the rebranded Pakatan Harapan alliance helmed by Mahathir.

The one-time prime minister quit the United Malays National Organisation (Umno), linchpin party of the ruling Barisan Nasional coalition, in 2016 citing a lack of confidence in Najib over his alleged involvement in the multibillion-dollar financial scandal at state fund 1MDB.

Umno serves to secure the support of the majority race in the country, the Malays.

Mahathir went on to create an alternative party, the Parti Pribumi Bersatu Malaysia (Malaysian United Indigenous Party), which together with older opposition parties such as Anwar’s Parti Keadilan Rakyat (National Justice Party) and the Democratic Action Party (DAP), and the PAS breakaway party Parti Amanah Negara (National Trust Party), form Pakatan Harapan.

It appears to be a complex web, but put simply, there are two camps – the ruling coalition and the opposition coalition, and then there is PAS.

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In this election, PAS is contesting as a third force to fight for the Malay vote, with candidates fielded in 158 of the 222 parliamentary seats at stake. In the contest for control over 12 out of 13 Malaysian state assemblies, PAS is fielding 393 candidates. Some 505 state seats are up for grabs on May 9.

These are big numbers given how PAS is a smaller party now, sparking speculation all around.

Mahathir and his Pakatan Harapan coalition are convinced that PAS is fielding candidates in more than double the number of seats it contested in 2013 under instruction from the ruling coalition, in order to split the anti-Barisan Malay vote.

The Islamist party’s current leader, Abdul Hadi Awang, has rejected such accusations but says he is open to forming a coalition federal government with Najib.

Azizuddin Mohamad Sani, a politics professor at the Northern University of Malaysia, said any “spoiler effect” – where PAS takes away crucial votes from Pakatan Harapan – is likely to be contained in rural and semi-rural seats where Malay Muslims make up 85 per cent of the voting population.

Hadi Awang says he is confident of winning at least 40 seats.

THE CLERIC’S SON

PAS’ hardening of its Islamist position – the reason it was forced to leave the opposition – could be a boon for Mahathir’s alliance.

Since the split, many of its moderate members have defected to Amanah, which focuses on advocating a brand of political Islam fit for multiracial Malaysia.

Amanah’s latest high-profile recruit is Nik Omar Nik Abdul Aziz, the eldest son of the party’s late icon and spiritual leader Nik Abdul Aziz Nik Mat, a figure who was nationally respected for his modest lifestyle and moral steadfastness.

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Nik Omar’s last-minute decision to defect from PAS – he was immediately sacked from the party his father helmed for 24 years – has caused deep rancour within his family.

But his refusal to respond to attacks from PAS as well as an understated personality have quickly made him an overnight media darling, with commentators comparing him with his father’s gentle yet charismatic ways.

His emergence signals to pious rural Malays that Amanah is a viable alternative to PAS, according to political observer Awang Azman Awang Pawi.

Nik Omar is running for a state assembly seat in the state of Kelantan, held by PAS for the past 28 years.

If previously there was talk that the northern state could finally fall to the ruling coalition, now the Nik Omar factor is slowing the winds of change.

THE FINANCE WHIZZ

Mahathir’s stunning defection to the opposition and reconciliation with his long-time rival Anwar Ibrahim stunned many, so it was not surprising when Daim Zainuddin, another of his one-time allies, joined hands with him this week.

Unlike Mahathir’s relationship with Anwar, Daim and the opposition chief were never estranged.

The 80-year-old Daim, however, retreated from public life after he retired from politics in 2004.

Daim, a businessman who was roped in twice by Mahathir to be his finance minister – the second time was during the height of the Asian financial crisis when the Malaysian ringgit came under attack – remains a member of Umno.

This week he appeared in public to show support for Pakatan Harapan candidates, citing an urgent need to fight for “justice for the people”. He said he was unafraid of being taken to task by Umno.

He joins other Mahathir allies, such as former trade and industry minister Rafidah Aziz and former foreign minister Rais Yatim, all Umno veterans. The sum effect of the defections is the mainstreaming of Mahathir’s party, only adding to its legitimacy.

Umno's secretary general Tengku Adnan Mansor on Saturday said the trio had been sacked from the party.

MUCH A-DO OVER POSTERS AND A ROCKET

University of Malaya politics professor Awang Azman said another quirk of the hustings that caught his eye was the election commission’s demand that pictures of Mahathir and Anwar were not to be used in Pakatan Harapan’s posters and billboards nationwide.

The body, statutorily independent, said this was in line with election rules that stipulate that only the pictures of the top two leaders of a candidate’s party or coalition can be used in electioneering material.

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Mahathir does not qualify as a top leader because Pakatan Harapan was not registered as an official coalition before elections were called. Among the reasons for this is his constituent party’s run-ins with the Registry of Societies over administrative kinks.

Mahathir accuses the election commission and the Registry of Societies of being in cahoots with Najib to derail his chance of taking power. Both bodies say these claims are baseless.

“The irregular rules concerning Anwar and Mahathir confirms that Barisan Nasional is concerned about their influence,” Awang Azman said.

Whether the absence of their posters will diminish their popularity or add to their “forbidden fruit” appeal is a question analysts are watching.

Meanwhile, on the issue of symbolism, the DAP sacrificed its half-century old rocket symbol to ensure smooth registration of the opposition coalition with the authorities, a move that emotional party veterans warned could upset or cause confusion to its long-time supporters. Whether they’re upset enough not to vote for the party remains to be seen.

BORNEO WINDS

“Sabah will not stop supporting the Barisan Nasional through thick and thin!” Najib declared on the campaign trail this week. The state of Sabah has long been touted as the ruling coalition’s “safe deposit” but a charge by a deposed Najib lieutenant may alter that.

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Shafie Apdal, until 2015 a vice-president in Umno, is hoping his newly formed Parti Warisan Sabah will be able to wrest a majority of the state’s 25 parliament seats to help Pakatan Harapan meet the magic number of 112 seats needed to form the federal government.

Shafie formed the party after he was removed from Umno over his public criticism of Najib for his handling of 1MDB’s troubles. Experts say Shafie will face an uphill task unseating Barisan Nasional in a state notorious for its multi-cornered election battles.

Voting patterns in the state are also complicated by block voting among its various indigenous groups loyal to their respective leaders.

Sabah’s racial composition is distinct from peninsula Malaysia, with Kadazandusuns, Bajaus, ethnic Malays and Chinese making up its population of 3.5 million people.

The state’s chief minister Musa Aman and the Bajau federal minister Salleh Said Keruak, both Umno men, together have a stranglehold on the Malay and Bajau communities, according to Sabah politics researcher Arnold Puyok. “In order to win, Warisan president Shafie Apdal must first break this unity,” Puyok said. The University of Malaysia Sarawak professor said Shafie is also disadvantaged because of his informal alliance with Mahathir, who is viewed unfavourably by many Sabahans.

The former premier is seen by many in the semi-autonomous state as the chief reason some of their rights under a 1963 agreement promising autonomy have been gradually eroded.

Puyok forecasts Shafie’s Warisan to win just four parliament seats.