PETALING JAYA (THE STAR/ASIA NEWS NETWORK) - Malaysia's two biggest opposition parties have agreed on the terms of a formal electoral pact set to be unveiled next month, a move that could threaten many seats won by the ruling Pakatan Harapan (PH) in the last general election.

Working together, former ruling party Umno and its former nemesis, Parti Islam SeMalaysia (PAS), could expect to win more seats at the next general elections, which must be held four years from now.

Under the agreement, both Malay/Muslim-based parties will not contest against each other in state and parliament seats, paving the way for straight fights with the PH coalition.

"The terms of the pact were finalised and agreed to in a meeting between our parties last week. We are now trying to find a suitable date and venue for the ceremony to launch and sign the Umno-PAS charter," Umno secretary-general Annuar Musa told The Star.

He said there was no need for the pact to be approved at Umno's annual general assembly in November because its supreme council had given its endorsement.

In the May 2018 general election, PH came to power unexpectedly, partly because Malay votes were split three ways as Umno, PAS and PH stood against one another in many seats.

The four PH parties, plus its Parti Warisan Sabah ally in Sabah, won a total of 121 wards, above the minimum 113 needed to win control in the 222-seat Lower House.

Umno-led Barisan Nasional won 79 seats and PAS another 18.

Today, the PH + Warisan alliance holds 129 seats in Parliament after a spate of defections.

An analysis by The Star newspaper showed that there were 21 parliamentary constituencies that Umno and PAS would have won outright had they combined forces in 2018.

In these wards, the total votes garnered by Umno and PAS were more than those garnered by the PH candidates.

Seven of these 21 wards were in Kedah, three each in Selangor and Perak, and two each in Pahang and Negeri Sembilan. There were also one seat each in Perlis, the Kuala Lumpur federal territory, Melaka and Johor.

The Star analysis also showed that Umno and PAS votes combined would have won an extra 45 state-assembly constituencies.

These would have meant Umno and PAS controlling the Kedah and Perak state assemblies, instead of losing them to PH.

Tan Sri Annuar, in his remarks to The Star said the pact would for now involve only Umno and PAS.

"However, we aim to eventually expand this agreement to include other parties so that it will cover the interests of all groups in the country," he added.

A name has also been agreed on for the pact, which will be announced at the launch ceremony.

Mr Annuar said the launch would be attended by party leaders, including Umno president Ahmad Zahid Hamidi and his PAS counterpart, Datuk Seri Abdul Hadi Awang.

On Sunday, PAS deputy president Ibrahim Tuan Man was reported as saying that the agreement between the two parties, which he described as a charter, would also involve several other groups, including non-government organisations.

He said some PAS officials who were part of a PAS-Umno committee to discuss the pact had to be replaced after they were voted to other positions in PAS during the party's internal polls in June.

As such, PAS had requested that Umno delay in launching the pact to give new committee members time to get up to speed.

Asked about the delay request, Mr Annuar said Datuk Tuan Ibrahim had mentioned September as a possible date for the launch of the pact.

"We agreed on a date in September, but we are now trying to get an earlier date as everything is ready," he added.