KUALA LUMPUR, Jan. 26 (Xinhua) -- Malaysia's ruling Pakatan Harapan (PH) coalition lost a parliamentary by-election on Saturday in its first electoral setback since coming to power last May.

PH failed to wrest the parliamentary seat of Cameron Highlands in the central state of Pahang from former ruling coalition and now opposition Barisan Nasional (BN).

According to the Election Commission, BN retained the parliamentary seat with a majority of about 3,000 votes, greatly outperforming its majority during the general elections in May last year, when it lost power for the first time since Malaysia's independence in 1957.

The parliamentary seat has been in a traditional BN stronghold with PH having previously said winning over voters in the area would be a difficult task.

The by-election was called after the country's election court ruled that the previous member of parliament had used corruption to sway voters, nullifying the result.

BN candidate Ramli Mohd Nor is a local and a member of a indigenous ethnic group. He defeated PH candidate M. Manogaran who had been fielded during the 2013 and 2018 general elections.

Seen as an indicator if BN supporters would side with the incumbent government, the victory is the first by BN after losing four previous local elections since the general elections.

The defeat came as a blow for the government with Prime Minister Mahathir Mohamad joining the campaign trail along with several serving cabinet ministers and Mahathir's designated successor and former deputy Prime Minister Anwar Ibrahim.

On the other hand, former Prime Minister Najib Razak, who is facing multiple corruption charges, actively campaigned for BN during the by-election.