(May 9): Many of the half a million Malaysians living and working in Singapore crossed the strait into their homeland late on Tuesday to cast their votes in Wednesday's national election, packing a busy causeway in a chaotic but at times festive mood.

A vote called for the middle of the week made for difficult logistics for Malaysians living in the city-state neighbour, having to take days off from work to travel across what is normally one of the world's busiest international borders.

"Having the election on a Wednesday is very inconvenient for Malaysians living in Singapore," said Pang Sze Lu, 31, who works in the manufacturing industry in Singapore, as she waited for a late-night train into Malaysia at the Woodlands checkpoint.

Malaysian Prime Minister Najib Razak's ruling Barisan Nasional (BN) coalition is facing its toughest election yet, going up against former premier Mahathir Mohamad.

A survey by independent polling firm Merdeka Center said BN had lost more ground in the lead-up to the polls, but it could still win enough parliamentary seats to cling on to power.

It said as many as 16 percent of Malaysia's parliamentary seats are too close to call and that voter turnout would be a critical factor in determining the outcome in those districts.

Some civic groups fear the mid-week election was discouraging Malaysians in neighbouring Southeast Asian states to vote, as they are not entitled to cast ballots in absentia.

But some were going the extra mile to vote like Arriane Chan, who began a 13-hour van ride from Singapore's Harbourfront terminal to Penang in Malaysia's northwest to cast her first ever vote, after missing the chance to book a flight home.

"I am feeling a little proud to be going home," said the 24-year-old who works for a food caterer in Singapore. "I will finally be able to participate and change politics in Malaysia."

Amid concerns about traffic on the main crossing into Malaysia, online postings urged those including Singaporeans who do not need to travel on crucial business to avoid it in the hours running up to election day.

Singapore authorities denied social media posts which alleged that travellers heading for Malaysia were stranded at immigration checkpoints.

Some companies, including Swedish furniture store IKEA, public relations firm Gloo PR and marketing consultant IFoundries, are giving Malaysian employees a paid day off.

Founder of Gloo PR, Oo Gin Lee, who is Malaysian but a resident of Singapore for 35 years, said he would not be voting this year, but wanted to give his Malaysian employees the chance.

"Even though I have been living in Singapore since young, I am still a Malaysian and I want to let young people have a chance to vote," he said. "It is just one day of work and it's the right thing to do."

Many Malaysian booked early flights back home, like Edward Pook, who flew Monday evening to Petaling Jaya.

"Even though my area is an opposition stronghold, I wanted to contribute to the win," Pook, who is an analyst at Singapore's DBS Bank said.

Others were forced to sit out the voting as it proved impossible to juggle the demands of work and travel arrangements home, even though additional flights were provided by budget carriers AirAsia and SilkAir.

"I am unsure what the rationale is behind the given date," said Lleufer Sinsua, 29, who works for a Swiss company.

"I believe the Election Commission should have been more inclusive for Malaysians working around the region who have no access to postal voting."