Millions of Malaysians have begun voting in tight national elections that could see the long-ruling coalition ousted after nearly 56 years in power.
Incumbent prime minister Najib Razak has voiced confidence that the National Front coalition will remain Malaysia's dominant political force despite facing its most unified opposition challenge since independence from Britain in 1957.
Opposition leader Anwar Ibrahim's three-party alliance hopes widespread grievances over how the National Front has struggled with accusations of arrogance, abuse of public funds and racial discrimination will translate into a surge of votes to propel the opposition into power.
Tens of thousands of Malaysia's 13.3 million registered voters lined up at schools and other voting centres on Sunday to cast their ballots at the beginning of a 10-hour voting period.
The National Front held 135 seats in the 222-member Parliament that was dissolved last month. It is anxious to secure a stronger five-year mandate and regain a long-time two-thirds legislative majority that it lost in 2008.
Mr Najib says only the National Front can maintain stability in Malaysia, which has long been one of South-east Asia's most peaceful and relatively wealthier countries.
"Your support is paramount if we are to keep to our path of development, if we are to continue our journey towards complete transformation," Mr Najib said in a statement to voters. "This election is about fulfilling promises, bringing hope and upholding trustworthiness."
Many political observers believe the race will be tight, with the National Front potentially edging out Mr Anwar's alliance partly because of its entrenched support in predominantly rural districts.
The opposition is likely to retain control of at least two of Malaysia's 13 state legislatures and should perform well in urban constituencies where a growing bank of middle-class voters have clamored for political change.
If the opposition wins, it would mark a remarkable comeback for Mr Anwar, a former deputy prime minister who was fired in 1998 and subsequently jailed on corruption and sodomy charges that he says were fabricated by his political enemies. He was released from jail in 2004 and now leads the biggest threat to the National Front.