Prime Minister Najib Abdul Razak has been busy crossing his opponents off his list in recent days.

It has been almost a year since Najib moved to quell an internal revolt in Umno, sparked by reports of multi-billion ringgit deposits in his personal bank accounts in July last year, which Najib claimed was a "donation".

So, why is he only now trying to put the final nails in the coffin by having Umno deputy president Muhyiddin Yassin and Umno supreme council member Mukhriz Mahathir sacked from the party?

Analysts agree that a previously cautious Najib now feels emboldened after BN's victory in the Sarawak election, as well as the Kuala Kangsar and Sungai Besar by-elections.

"Najib is consolidating his position in Umno. After winning the two by-elections and the Sarawak election, Najib has further strengthened his position.

"Thus, it is good timing to kill off his major detractors in the party," said senior fellow at the UKM's Institute of Malaysian and International Studies Faisal Syam Abdol Hazis.

Apart from the sackings, the Umno supreme council also unanimously decided to suspend Umno vice-president Shafie Apdal and cut funding to former prime minister Dr Mahathir Mohamad's Perdana Leadership Foundation.

Echoing this is James Chin of the University of Tasmania's Asia Institute.

"The wins at the by-elections gave Najib the political capital to move (against his opponents)," Chin said.

Both also agree that Najib appear to have won the battle within Umno.

"Najib is in total control of Umno now," said Chin.

Chin added that Najib made his move after it became apparent from by the by-elections that the Umno rebels could not create a groundswell of discontent among the Malay electorate.

Meanwhile, Faisal said Najib began charting the course of his victory when he purged Muhyiddin and Shafie from the government in July last year.

"I think Najib won the battle a long time ago when he sacked Muhyiddin and Shafie from the cabinet. He's now just consolidating and strengthening his position.

"Najib has shown that he can still win elections, unlike Mahathir's narrative that BN would collapse under Najib's stewardship," he said.

The final move to consolidate his power will be a cabinet reshuffle, which Najib is expected to announce this afternoon.