Five days before national elections that are expected to return Malaysia's government to power, Prime Minister Mahathir Mohamad and his ruling coalition should be coasting along on cruise control.

The economy has posted a better-than-expected 8.1 percent growth rate this quarter, confirming that the recession is over. Mahathir's economic policies, including currency controls, appear to have been vindicated. He has weathered criticism unleashed by the firing, jailing and beating in detention of his popular former deputy, Anwar Ibrahim. And newly united opposition parties have shown signs of clumsiness, indicating they are not ready for prime time.

But rather than acting like a government certain of an easy victory, Mahathir's coalition has resorted to negative advertisements usually reserved for candidates running scared. And Mahathir has been barnstorming at a frenetic pace, warning of dangers he says would come with an opposition victory in Monday's vote and accusing rivals of being backed by the foreign media or other dark, outside forces trying to rob Malaysia of its independence.

Acting on the unsubstantiated reports of foreign involvement, his Foreign Ministry called in diplomats from the United States, Britain, Canada and Australia today and warned them to keep out of the campaign. The embassies have denied any involvement.

This is "the dirtiest election ever," said opposition candidate Chandra Muzaffar, an academic. "The national leadership has shown no qualms about using the foulest and filthiest tactics to win the elections."

Chandra was speaking after the surreptitious release overnight of a new videotape reviving the allegations of sodomy against Anwar, including purported confessions from three men who claim to have had sex with him. All three have since retracted their confessions, saying they were coerced.

Chandra called the videotape "political pornography" and has formally asked the police to investigate how the tape appeared at bus stops and marketplaces.

The videotape came after a series of full-page newspaper advertisements lampooning key opposition leaders and urging voters to return the National Front to power. One ad today carried a large, fuzzy picture of Anwar's wife, Wan Azizah Ismail, who is running for her jailed husband's old parliamentary seat. Over the photo is the large-type headline, "Even she doesn't trust her husband."

"They are actually attacking me," Azizah said in an interview. "I think they have no other issues to talk about. That's why they are putting out all these ads. But I think it will have a boomerang effect."

She added, "It is a big smear campaign."

The unanswered question is why a ruling coalition that seems guaranteed easy victory would resort to such campaigning. Some here believe Mahathir, at 73 Asia's longest-serving elected leader after 18 years in power, is running not simply to win but to pile up as large a victory margin as possible to ensure his legacy after what is likely to be his last campaign.

Even a major gain in seats by the opposition would hardly affect how the country is governed. Malaysia's prime minister is an all-powerful executive and the parliamentary opposition plays a sideline role of speechmaking and criticizing. So this election seems more about symbolism than substance, with Mahathir wanting a big win mainly as a matter of saving face and the opposition laying groundwork for the next election five years hence.

The Anwar episode has also badly split Malaysia's dominant ethnic Malay community, which controls politics. Mahathir and his multi-ethnic ruling coalition is likely to be returned to power by a large majority. But a loss of parliamentary seats among Malay voters, particularly in the northern states that make up the Malay heartland, would mark a humiliating setback that could spark a revolt within his own United Malays National Organization(UMNO) party.

In the last parliament, which was just dissolved, the National Front, with UMNO as the lead party, held an overwhelming 166 seats out of 193. The newly united opposition, called the Alternative Front, is keeping its hopes modest, seeking only to increase, or perhaps double, the number of seats it holds, to 40 or 50.

"Urban Malays will probably vote against the government," said Razak Baginda, executive director of the Malaysian Strategic Research Center, a generally pro-government research organization. "In the rural Malay heartland, their aspirations are not about justice--their aspirations are about a new road, a new mosque."

"I don't think Malays are upset that Anwar was sacked," said a Western diplomat, noting that Anwar and Mahathir are both Malay. "The rub was the way he was treated, in a very un-Malay style, dragging out the dirty laundry in public, doing everything in your power to humiliate him."

A best-case scenario for the opposition would be to deny the ruling coalition a two-thirds majority and maybe gain control of an additional state government or two. But even that is considered unlikely given the government's vast resources, its control of the media, and a neighborhood network system that has a party member monitoring every 10 households in the country.

"A good showing would be a break in the two-thirds monopoly," said opposition stalwart Syed Husin Ali, a member of the Alternative Front. "Winning is still distant."