KUALA LUMPUR (Reuters) - Malaysia’s ruling coalition lost a state constituency in a by-election on Saturday in a further sign of declining public support for Prime Minister Mahathir Mohamad’s alliance.

FILE PHOTO: Malaysia's Prime Minister Mahathir Mohamad reacts during an interview with Reuters in Langkawi, Malaysia March 28, 2019. REUTERS/Feline Lim

It is the third defeat for Mahathir’s Pakatan Harapan coalition, or Alliance of Hope, in local elections since it took power in May last year.

Its candidate, Streram Sinnasamy, lost the Rantau constituency in Negeri Sembilan state by 4,510 votes to Mohamad Hasan, the acting chairman of Barisan Nasional, the main opposition coalition.

Mohamad was appointed to the post after scandal-plagued former prime minister Najib Razak led Barisan Nasional to its first defeat in more than 60 years in last year’s national election.

Mohamad had won Rantau unopposed in 2018, but a Malaysian court later found errors in electoral procedure and called for a new poll.

His win is the latest blow for Mahathir’s coalition, which has faced criticism for failing to deliver on promised reforms and protecting the rights of majority ethnic Malay Muslims.

Polls consistently show that the coalition has been losing support among the Malays, some of whom fear that affirmative-action policies favoring them in business, education and housing could be taken away.

Anwar Ibrahim, a former deputy prime minister who is widely expected to succeed Mahathir, had actively campaigned in Rantau in a bid to garner support away from Mohamad, seen as a highly popular figure among Malays.

Meanwhile, Najib, an active public presence during two previous by-elections, was largely absent on the Rantau campaign trial as he faced the first of several corruption trials earlier this month.

Najib is facing more than 40 charges of money laundering and other offences over the alleged loss of billions of dollars from state fund 1Malaysia Development Berhad.