An opposition candidate won by a landslide in a Singapore by-election on Saturday as voters handed a stinging rebuke to the ruling party in a poll seen as a referendum on their recent reforms. The Workers' Party retained the seat in the district of Hougang, winning 62.09 percent of votes cast despite having to fire the previous member of parliament over allegations of extramarital affairs. The ruling People's Action Party (PAP) received 37.91 percent, the elections department said. Prime Minister Lee Hsien Loong and other PAP big guns had gone all out to campaign for the ruling party candidate, Desmond Choo, but in the end failed to win control of the ward, which has been in opposition hands for the past 21 years. The vote took place a year after the ruling party, which has been in power more than half a century, suffered its worst performance in a general election. The Hougang seat was left vacant in February after the Workers' Party sacked its representative over allegations of extramarital affairs, giving the PAP an opportunity to redeem itself. In last year's elections, the PAP was jolted when it received an all-time low of 60 percent and the opposition grabbed an unprecedented six seats in the 87-member parliament. The PAP holds the rest. Issues such as a liberal immigration policy, a growing income gap, high salaries for cabinet ministers and overcrowding in public transport hit the PAP vote, analysts said. The PAP-led government swung into action after the general election rebuke, stepping up construction of public housing, budgeting hundreds of millions of dollars to upgrade public transport, and reducing the foreign worker intake. Cabinet ministers also took a pay cut but they remain the highest-paid politicians in the world, with the prime minister on a basic annual salary of Sg$2.2 million ($1.73 million). Singapore says the high salaries are designed to deter corruption and attract talented people from the private sector. Workers' Party Secretary General Low Thia Khiang described the win by the party's Png Eng Huat as a "very good result" but slammed the PAP for what he described as "character assassination" during the campaign. Prime Minister Lee said in a statement he was disappointed about the loss but was encouraged that the party had managed to increase its share of the popular vote. He noted that the 37.91 percent PAP got in Saturday's by-election was an improvement on the 35.2 percent it polled in Hougang last year and 37.3 percent in 2006. "I respect the choice of Hougang voters. The PAP will continue to be present in Hougang, and I am confident that we will win back the constituency in a future election," Lee said. He also said the reforms initiated by the government will continue. "Since the general election in May 2011, the PAP government has done its best to address important national issues like housing and transportation, immigration and population, economic upgrading and workers' incomes," he said. "We have made progress, but there is much more to be done." Apart from national issues, many Hougang residents are angry at the PAP's policy of putting opposition wards at the back of the queue for upgrades of public-housing estates, where more than 80 percent of Singaporeans live. Hougang is a lot scruffier than neighbouring PAP-controlled wards, which receive priority for facelifts and other improvements that boost property values.