By (AFP) Kuala Lumpur – ''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 delegitimizing 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.