KUALA LUMPUR (REUTERS) - Kasthuribai Sattayappan's teenage son died in January when he was hit by a chair thrown from an upper level of the public housing flats in the Malaysian capital Kuala Lumpur.

"The lifts don't work and no one comes to remove the rubbish so they just throw everything out of the window," Kasthuribai told Reuters at the filthy and broken-down apartment block.

The youth's death sparked a wave of outrage over the state of public housing projects in the city's poorest areas, fuelling urban opposition to Prime Minister Najib Razak's Barisan Nasional (BN) coalition ahead of next week's general election.

Malaysia's urban population is growing rapidly as people migrate from rural areas in search of better jobs. Many of them blame the government for soaring living costs, decayed public housing, poor education and healthcare, and congested roads.

"People are beginning to vote for other parties because they see that our current government is not leading us towards a better country," said 27-year-old Leen Low, who moved to Kuala Lumpur five years ago from a semi-rural town.

Despite the growing ranks of angry urban voters, however, Najib is widely expected to win another term in the May 9 election on the back of rural votes and the disproportionate share of rural constituencies in the 222-seat Parliament.

Malaysia's urban population percentage, 76 per cent, is South-east Asia's largest after city-state Singapore and Brunei, according to UN data.

But only 97 parliamentary constituencies, about 44 per cent of the total, are classified as urban and semi-urban, according to political research firm Politweet.org.

Opposition parties won control of the state assembly in Malaysia's most urbanised states, Selangor and Penang, for the first time in 2008.

They are expected to retain power and possibly tighten their grip in these states in next week's poll, when federal and state lawmakers will be elected simultaneously.

Urban opposition to the government is not confined to the poor living in rundown districts - there is the middle class too.

About 200,000 people flooded Kuala Lumpur's streets in 2015 to protest against a new goods and services tax (GST) that sent costs rocketing and Najib's alleged involvement in a multi-billion-dollar scandal at state fund 1Malaysia Development Berhad (1MDB).

The Prime Minister has repeatedly denied any wrongdoing.

MALAY VOTE BANK

There have been no protests on that scale since then, but young urbanites are active on Twitter and Facebook urging voters to oust Najib.

But the Prime Minister can still count on the country's majority ethnic Malays and other Malaysians living in rural areas, long a solid vote bank for his United Malays National Organisation (Umno).

For these voters, livelihood problems that Umno can solve with subsidies and development spending are far more important than issues of corruption and social injustice that the opposition argues about.

The fewer number of voters in rural constituencies means they are easier for BN to win.

"In Malaysia, we don't have the 'one man, one vote' principle," said James Chin, director of the Asia Institute at the University of Tasmania, Australia, noting that the number of votes contestants need to win in some rural constituencies is a fraction of the tally needed in urban areas.

In the 2013 election, BN lost the popular vote but still won a majority of parliamentary seats. Just 20 per cent of its 133 seats were urban, according to Politweet.org.

Critics say the odds have been stacked further in the government's favour this time because of electoral boundary changes made by the Election Commission last month.

They say that large numbers of opposition-leaning urban voters were stuffed into densely populated constituencies.

The Election Commission and BN deny charges of gerrymandering.

Still, with the urban population projected to climb to 80 per cent by 2025, city voters could become an increasingly large threat to BN's hold on power.

Former leader Mahathir Mohamad, who quit Umno and is now leading the opposition push to topple Najib, says he expects a "Malay tsunami" next week.

Independent polling firm Merdeka Centre has predicted that about 8 per cent of Malay votes would swing to the opposition.

Abdul Rahman Dahlan, BN's strategic communications director and government minister in charge of economic planning, says the government is aware of issues alienating urban voters.

BN's election manifesto promises three million new jobs, public transport improvements and more affordable public housing.

"We do understand that there is a big divide in terms of political leanings," Abdul Rahman told Reuters.

"But we have been working very hard to ensure that the urban people understand what the government has been doing."