"Phantom" voters, electoral roll tampering, mysterious power blackouts during recounts -- Malaysian activists are gearing up to battle widespread cheating at what they fear will be the dirtiest election in the country's history.
Prime Minister Najib Razak is facing a tough test at the May 9 poll due to a corruption scandal surrounding state fund 1MDB, discontent over rising living costs, and a challenge from veteran ex-leader Mahathir Mohamad.
While vote-rigging has plagued previous Malaysian elections, observers fear the high stakes mean that cheating by the long-ruling Barisan Nasional (BN) coalition will be more rampant than ever before.
In response, opposition and civil society groups are training poll monitors to prevent fraud, while leading electoral reform group Bersih has set up an online platform to report instances of alleged rigging.
"This election is not just dirty, it is filthy," Bridget Welsh, a Malaysia expert from John Cabot University, told AFP. "Najib's insecurity is delegitimising the electoral process."
Even before a single ballot has been cast, Bersih lamented the poll had descended into an "open auction with votes for sale" due to local leaders -- mainly from BN but also the opposition -- giving out cash and gifts such as TVs and food hampers.
Concerns have been raised about the electoral roll, with Bersih saying that it had so far received over 80 complaints from the public.
These include reports of so-called "phantom" voters, such as people who have died but still appear on the list, or people whose names have appeared without them registering.
At the last election in 2013, when BN lost the popular vote for the first time since Malaysia gained independence from Britain in 1957, there were numerous allegations of cheating.
There were reports of "dubious" voters including foreigners being flown into key constituencies in Malaysia to vote for BN.
Supposedly indelible ink, used in a Malaysian general election for the first time and touted by the government as a guarantee against multiple voting, was found to wash easily off people's fingers.
Sudden electricity blackouts at polling centres were also experienced during vote recounts, fuelling suspicions of ballot tampering -- something the ruling coalition denied.
In the hope of stemming what they expect to be a tsunami of cheating, Bersih and other groups are training volunteers to monitor voting on polling day.
At a recent session in a Kuala Lumpur hall, about 100 volunteers were being given pointers by Invoke, a think-tank linked to opposition group the People's Justice Party.
They gathered around trainers who were pretending to be polling agents and teaching them how to check for suspicious activity.
"We're doing this to ensure nothing funny happens on polling day," Invoke official Matthew Lai told AFP. "There are too many avenues to cheat."
Despite their efforts, Bersih -- which led massive protests against Najib at the height of the 1MDB scandal -- is not confident that reports of alleged violations will be taken seriously, and says complaints made at the last election were not.
There are some instances of alleged poll rigging that it is already too late to fight.
In March the government pushed a redrawing of electoral boundaries through parliament, in a move that critics say unfairly favours the ruling coalition by creating constituencies dominated by their Muslim Malay supporters.
BN however insists that Malaysian elections are conducted fairly.
"There's no such thing as cheating here... In our system, even the opposition can win," Information Minister Salleh Said Keruak told AFP.
Najib is tipped to retain power at the election. Critics say this will be partly due to vote rigging but admit other factors such as a robust domestic economy will help him.
Still the presence of 92-year-old Mahathir, who is heading the opposition, has made life more difficult for him.
Mahathir came out of retirement to take on Najib, his former protege, in response to the 1MDB scandal, which allegedly saw billions looted from the state fund in a campaign of fraud and money-laundering. Najib and 1MDB deny any wrongdoing.
While Mahathir has predicted enormous cheating, critics say this is rich coming from a man who faced numerous accusations of fraud at polls during his own time in office.
However, Welsh from John Cabot University said that vote-rigging has become more serious under Najib: "Elections are supposed to be a contest -- Najib wants it to be a beating."