Malaysia's unfolding election drama took a major twist this week when Tun Daim Zainuddin, the country's powerful former finance minister, declared that he was backing the opposition alliance and called on Malaysians to remove the ruling Barisan Nasional (BN) coalition government.

Mr Daim's support for the Pakatan Harapan coalition, which is led by his chief patron Mahathir Mohamad, has made political observers sit up. But they are divided over why he has done so.