Ruling party Umno holds its annual congress this week under pressure to show it has not abandoned a much-vaunted anti-corruption campaign, and that it remains in control of the debate on Islam.

Prime Minister Abdullah Ahmad Badawi declared the fight against graft a cornerstone of his administration after succeeding veteran leader Dr Mahathir Mohamad in 2003, but drew criticism after failing to claim many top scalps.

Then last month the party shocked the country by suspending cabinet minister Isa Samad for six years for buying votes in last year's internal leadership elections.

Isa was the most senior politician to be disciplined for graft and his fall from grace revived hopes Abdullah was serious about rooting out the corruption that has blighted Umno for decades.

But since then party chiefs have said that investigations into the elections, which were reportedly rife with "money politics", are closed and that no other figures are under suspicion - disappointing members and citizens alike.

"People come to me and ask, why is Isa caught? Is this a sign of selective prosecution? Because they've heard many more are involved," veteran Umno member Tengku Razaleigh Hamzah told AFP .

"Why do you stop at one? Why not go for the others? This is a welcome move, but the machinery is still not right," said the former finance minister.

Although no formal motions on corruption are expected to be passed at the meeting which begins Thursday, Malaysians will be watching the assembly for genuine signs of support for Abdullah's campaign.

Umno versus PAS

"If there is a lukewarm response on the matter, then the interpretation will be there is no solid backing for Abdullah," said parliamentary opposition leader Lim Kit Siang.

The party "must send a clear message to the prime minister and the country that Umno is fully committed to it," he said of the meeting, which is seen as a barometer for how government policy is likely to develop.

Another hot topic will be Umno's response to the hardline Islamic opposition, PAS, which recently refreshed its leadership ranks with more progressive figures after suffering a humiliating defeat in the 2004 general elections.

While PAS's calls for Malaysia to become an Islamic state with Syariah law have been shunned, Umno has successfully captured the middle ground by promoting "Islam Hadhari", which stresses moderation and economic and scientific progress.

"That sense of moderation is very important now for Malays and they want to be seen as moderate. In that sense, Umno has been successful," said Maznah Mohamad from Universiti Sains Malaysia's development studies department.

Umno is also expected to seek a resolution to a war of words between Mahathir and Trade Minister Rafidah Aziz, who have clashed publicly over the status of national car maker Proton.

Rafidah and Mahathir

Rafidah recently slammed Proton vehicles as "shoddy", reflecting the views of many Malaysians but enraging Mahathir, who launched the national car scheme in the 1980s and complains it is being treated unfairly by the government.

"The open discord between Rafidah and Mahathir will have to be put to rest so we can refocus our energies," said Shahrir Abdul Samad, a senior Umno leader, adding the party wanted to push ahead with a much-awaited national auto policy.

Mahathir, who stepped down as prime minister and Umno president in 2003, has gone on a European vacation and will skip the general assembly this year for the first time in more than two decades.

Umno events will kick off on Tuesday with sessions led by the youth and women's wings, and culminate in the three-day general assembly which starts on Thursday with some 2,500 delegates in attendance.

The party, which leads the National Front alliance in government, has headed Malaysia's multi-racial ruling coalition since independence from Britain in 1957.