KUALA LUMPUR - Former Premier Mahathir Mohamad said on Thursday (July 21) that Malaysians should push for a referendum on Prime Minister Najib Razak's leadership after US prosecutors filed lawsuits linked to state-owned fund 1Malaysia Development Berhad (1MDB), Reuters reported.

Tun Dr Mahathir's comments came as he launched a new opposition front, part of a bid by ruling party rebels and the opposition to join hands and fight against the scandal-tainted Najib.

Datuk Seri Najib has been facing persistent calls to step down over multi-billion dollar graft allegations tied to the state-owned 1MDB investment fund that he oversaw. On Wednesday, US prosecutors filed five lawsuits to seize more than US$1 billion in assets they said were tied to money stolen from 1MDB.

In a press conference Thursday, Mahathir also said Malaysians should have a "peaceful rally" to demand the removal of Najib. "Malaysians are timid. In other countries, millions take to the streets. Malaysians are very nice, we don't normally hold such (protests)," he was quoted saying by the Malaysiakini news website.

He also called on Malaysians to push for a referendum for Najib's leadership. "I suggest the people push for a referendum on the prime minister's leadership," Mahathir told reporters.

Mahathir on Friday announced his plan to form a new splinter party made up of rebels from Najib's ruling United Malay National Organisation (Umno), which will serve as a platform to work with his old foes in the opposition.

Mahathir, who ruled for 22 years, has made no qualms over his main objective, which is to oust Najib over his handling of 1MDB.

He has also found an unlikely ally in his quest to see Najib's ouster, with jailed opposition figure Anwar Ibrahim endorsing the new political compact spearheaded by Mahathir, despite previously having been arch-enemies.

Anwar, who is one year through a five-year jail term for sodomy, told Reuters there is "every reason" for the opposition to work with anyone who is committed to an agenda that pushes reforms, democracy and the rights of the people. "Our position is to collaborate with all progressive forces on a democratic reform agenda and pro-rakyat policies," he told Reuters from prison through an intermediary, using the Malay word for citizen. Anwar's supporters have maintained that the sodomy charge is politically motivated.

Anwar was at a court hearing this week when he provided the comments.

This is the second time Anwar has been sent to prison. He was first jailed by Mahathir on charges of sodomy and graft in the late 1990s, after he was sacked as deputy prime minister by Mahathir.

The new party mooted by Mahathir will be part of a greater coalition comprising Anwar's Parti Keadilan Rakyat as well as its allies in the Pakatan Harapan coalition - the Democratic Action Party and Amanah - along with NGOs and other individuals.

Mahathir said he is looking at ways to set up the party as soon as possible.

He also acknowledged that there may be problems and delays registering a new party and did not rule out taking over an existing one.

"We are aware that if we try to register a new party it is not going to be approved or it will be delayed for months and years. So we are trying to find a solution to that problem but we will set up this party and we will make a formal declaration of our objectives," he said, according to The Star.

Mahathir did not provide a timeline for the setting up of the party, but said he hoped it would be done as "as soon as possible".

Also present at the press conference on Thursday were lawyer turned politician Datuk Zaid Ibrahim, Amanah member Khalid Samad, former Cabinet minister Tun Dr Ling Liong Sik and former Bar Council chief Datuk S. Ambiga.

It is widely speculated that former deputy Prime Minister Muhyiddin Yassin - who was sacked by Najib last year - will step up to lead Mahathir's new party, lending influence from the southern Umno stronghold state of Johor. He could possibly be a candidate for prime minister should the opposition succeed in removing Najib.

Also in the mix is former Umno vice-president Shafie Apdal, whose resignation from the party sparked a mass exodus of Umno members from the Semporna parliamentary constituency of his home state of Sabah, another Umno stronghold.