Prime Minister Dr Mahathir Mohamad's chosen successor, Abdullah Ahmad Badawi, is often called "Mr Nice Guy".

But he faces a huge task in convincing the nation that he is up to the top job, which has been held with supreme authority by Mahathir for 21 years.

The possibility that Abdullah, now deputy prime minister, could soon be called upon to take over was raised at the weekend by Mahathir's resignation - later retracted - from his party posts.

Abdullah, 62, was appointed deputy premier in February 1999 to replace Mahathir's charismatic former deputy Anwar Ibrahim, who was sacked and jailed in September 1998.

Mahathir hand-picked Abdullah, who had been a strong opponent of Anwar within the ruling Umno, urging members not to contest the position during party elections.

The top two leaders of Umno traditionally assume the posts of premier and deputy premier, and Abdullah would be expected to replace Mahathir if he does quit.

"If Mahathir had actually resigned, Abdullah would have been the new prime minister. There is no dispute about it," said Lim Kit Siang, DAP chairperson.

"But the only question is whether Abdullah can uphold the premiership with authority or whether he will be challenged from inside UMNO," he told AFP .

Three vice-presidents

Lim said if Abdullah failed to perform up to expectations, he could be challenged by the three vice-presidents of UMNO - Najib Razak, Muhammad Muhammad Taib and Muhyiddin Yassin.

Lim's caution is based on the fact that three of Mahathir's previous deputies have perished politically.

Abdullah joined the civil service in the 1960s and, after catching the eye of Umno leaders, became a member of parliament in 1978 in the Kepala Batas constituency in Penang.

He went on to hold the education, defence and foreign ministry portfolios. He is married to Endon Mahmood and they have two children.

"Abdullah is a moderate and soft leader but he can be tough if situation demands," a government source told AFP .

The major challenge Abdullah would face outside his own party would come from the opposition PAS.

The party president, Fadzil Noor, died at the weekend and has been replaced until party elections next year by an Islamic hardliner, Abdul Hadi Awang.

Abdullah, however, has strong Islamic credentials, having majored in Islamic studies at University Malaya, and is seen as being more acceptable to a broad spectrum of Malaysia's multiracial population.

But the Malay Mail reflected widespread concern over the possibility of Mahathir's departure, asking in an editorial: "How does one find a replacement for an enigmatic and dynamic leader who has spearheaded so many advances for the country that it bears little resemblance to what it was when he first took office."