Deputy Prime Minister Muhyiddin Yassin has missed a golden opportunity to unseat his boss Najib Abdul Razak, after Umno decided to postpone party elections till 2018, said an Umno blogger.

Shahbuddin Husin claimed that Muhyiddin should have made a move after a leaked video of him calling for 1MDB's directors to be sacked went viral.

"Paired with former premier Dr Mahathir Mohamad's (photo) attacks on Najib, the momentum for Muhyiddin to oust Najib was at its peak when the video of his speech in Janda Baik went viral a few months ago.

"At that time, besides Umno being split on the government's handling of 1MDB, the people too hoped that something would have been done by Muhyiddin.

"But because this chance to act and be brave was let go just like that, the momentum for Muhyiddin (to boot Najib) has ended," he wrote in his blog today.

He blamed the Umno deputy president's lack of bravery and cautiousness for the missed opportunity at a regime change.

However, Shahbudin said while Muhyiddin may not sleep easy now, he still has a chance come the 14th general election.

"His chances will only shine bright again if the 14th general election results are worse (for BN) compared to the 133 (Parliament seats won) in the 2013 elections," he said.

Najib had on Friday announced that Umno party polls, slated to be held next year, would be postponed for 18 months, to further strengthen the party.

Observers have said the move is to ensure that Najib stays as premier until his current mandate ends.