Prime Minister Najib Abdul Razak and PAS president Abdul Hadi Awang have cast doubts on Pakatan Harapan's grip on Selangor, despite the coalition's affirmation that all is well.

Najib, in a blog posting today, cited alleged instability in the state to question Harapan's ability to govern the country.

"Currently in Selangor, the political situation is not stable, if PAS or DAP pulls out from the (state) government, the position of menteri besar and the state government would surely be affected.

"Imagine if this happened at the federal level. To ensure that economic development and that the people's welfare are protected, the government must be led by a coalition of parties that is solid, experienced, and of one mind," Najib said.

Meanwhile in an Utusan Malaysia report, Hadi indicated that a change of government in Selangor was possible.

"That is normal, it could possibly happen," Hadi is quoted as saying when asked about speculation that Selangor assemblypersons from PKR, PAS and Umno were trying to stage a coup in the state.

Hadi said PAS assemblypersons in Selangor would follow orders from the central leadership regarding any matter on the state government.

There are currently murmurs of PKR assemblypersons jumping ship to oust the party's deputy president Azmin Ali as menteri besar, although a number of assemblypersons have denied such speculation.

Azmin is returning from overseas today, and a purported message from the Selangor state assembly Backbenchers Club has asked all assemblypersons to be at the airport for a welcoming party.

Meanwhile, Najib took several other jibes at the opposition in the rest of his blog posting.

Among others, he said the constant in-fighting among the opposition would lead to constant cabinet reshuffles.

"As a result, continuity of basic services provided by the government will stop or be affected," he said.

Najib himself had reshuffled or made changes to his cabinet four times since 2014.

In one reshuffle in 2015, Najib axed his then deputy Muhyiddin Yassin and fellow minister Shafie Apdal.

He made further changes last year, when then-finance minister II Husni Hanadzlah chose to retire instead of being switched to another ministry.

Muhyiddin, Shafie, and Husni have all since either criticised or voiced concerns on Najib's troubled brainchild, 1MDB.