Former prime minister Dr Mahathir Mohamad said a slight nudge could bring down three BN state governments - Perak, Terengganu and Johor - even before the next general election.

Mahathir said this in reference to Jorak state assemblyperson Shahruddin Salleh who defected from Umno to Parti Pribumi Bersatu Malaysia (Bersatu) earlier this week.

"When something starts happening, it will gather speed. Others will follow suit.

"In Perak, it only takes two state assemblypersons (to defect); in Terengganu, it also needs two state assemblypersons.

"If they cross over, the governments fall. We can rule in these states – along with Selangor and Penang - without waiting for the 14th general election," he told a ceramah in Muar last night.

BN will lose its simple majority in both the 32-member Terengganu state assembly and 59-member Perak state assembly if two of its representatives defect to the opposition.

In Johor, Mahathir said if another 10 Umno state assemblypersons followed Shahruddin's example, the BN government in Umno’s traditional fortress would fall.

"We would become the government in Johor," said Mahathir.

Shahruddin's defection to Bersatu to serve as its secretary-general had caused BN to lose its two-thirds majority in the state.

BN still retains 37 out of 56 seats in the Johor state assembly.

"So ladies and gentleman, we only need to work a little harder. Do not be afraid to become Bersatu members," added Mahathir.

However, Mahathir acknowledged that the task was difficult, claiming that most MPs and state assemblyperson had been "bought" to support the current government.

Nonetheless, he emphasised the need for Bersatu to rapidly grow its membership base.

"If we become a big party, only then others will respect us," he said.

He also emphasised the need for Bersatu to work together with opposition parties if it wants to form the government.

Mahathir even used PKR-led Selangor as an example of what a Bersatu government and its allies will look like.

"We have seen how the parties of our (former) opponents can manage a state.

"Last time, I thought they know nothing about administration but to the contrary, when they became the government, they managed to do a lot of good thing, particularly for the poor," he said.

Azmin was at the ceramah when Mahathir delivered a speech. The ceramah was broadcast live on Facebook.