The annual general assembly of the ruling United Malays National Organisation (UMNO) starts on Monday, and 2,400 delegates had been braced for a confrontation between the two men amid an ugly feud. However, Mahathir suffered a mild heart attack last week and over the weekend announced he would miss the meeting.
Veteran political analyst Chandra Muzaffar said plans by UMNO members, who had been expected to attack Mahathir and rally around Abdullah, have been neutralised by Mahathir's shock illness.
"I think if there was efforts to orchestrate an attack on Mahathir it will fizzle out with him lying in bed," he told AFP.
"Attacking someone who is in hospital will be seen as uncouth," he added.
Abdullah, 66, will still face questions over his performance after three years in office, including doubts raised by Mahathir, which have resonated with some delegates.
"There will be more attention on various issues of his governance," said Chandra.
Mahathir, 81, has attacked Abdullah's administration for months, levelling accusations of economic mismanagement, nepotism and corruption -- charges Abdullah, also UMNO president, has repeatedly denied.
Abdullah also faces dissatisfaction from UMNO's ranks for weak leadership and failing to live up to his election promises of battling corruption.
Meanwhile, economic growth has been steady but not spectacular, while foreign investment has fallen.
Shamsul Amri Baharuddin, an UMNO observer who teachers sociology at the National University of Malaysia, said Abdullah would be under pressure to rebuff Mahathir's allegations.
"Abdullah is now worried. UMNO members will demand answers to Mahathir's allegations. Some believe there is substance to Mahathir's claims. They will be blunt with Abdullah," he said.
UMNO secretary-general Mohamad Radzi Sheikh Ahmad has already signalled the floodgates will be open, announcing delegates are free to speak and even attack government policies.
"UMNO has never issued any directive not to talk about certain issues," he told reporters.
Besides answering Mahathir's accusations, Abdullah was also be called to account for the economic wellbeing of the country's majority ethnic Malays, who make up some 60 percent of Malaysia's 27 million population.
UMNO was established in 1946 to protect the interests of the Malays, and strives to boost their economic status, with the ethnic group lagging behind Malaysia's minority Chinese community.
Its power is derived from voters in rural areas, where the bulk of the Malay population lives. Many of them are land owners, but remain impoverished despite relentless government efforts to improve their lot.
Another problem faced by Abdullah's regime is the high unemployment rate among Malays.
A government survey last year found most unemployed graduates were Malays with poor English language skills who had undertaken university degrees irrelevant to the workplace.
Malay and other indigenous graduates make up 49,000 out of nearly 67,000 unemployed graduates, reports said last November.
Shamsul said UMNO members are also unhappy with Abdullah's administration because few development programs and lucrative government contracts -- traditionally responsible for creating wealth -- had reached them.
"A lot of UMNO members are disappointed with Abdullah. Many depend on the party for government contracts in return for political support. Some 70 percent of the delegates are from this group," he said.
The meeting comes amid talk of snap polls next year after Abdullah postponed internal party elections due in 2007, a move seen as avoiding disunity in UMNO, which is the lynchpin of the ruling National Front coalition.
Malaysia's last general election was in March 2004, which Abdullah won in a landslide. The latest possible date for the next election is March 2009.
UMNO vice-president and agriculture minister Muhyiddin Yassin said the party was firmly behind Abdullah and urged delegates to focus on nation-building efforts such as the promotion of moderate Islam in the majority-Muslim country.
"We are getting closer to an election. We need to strengthen our party's networking," he told AFP.

Copyright AFP (Agence France-Presse), 2006