Zimbabwe opposition leader Morgan Tsvangirai's skill as an orator has been one of his greatest strengths in a campaign against President Robert Mugabe's 20-year government.

But critics say the leader and co-founder of the young Movement for Democratic Change (MDC) is less convincing in private. Some foreign diplomats find him weak on policy detail and uninspiring for a man who hopes to form the next government.

Nevertheless, the MDC poses a serious threat to Mugabe's ruling ZANU-PF party in parliamentary elections this weekend.

If ZANU-PF suffer a defeat at the polls, Tsvangirai has said Mugabe will be forced to negotiate with the opposition during the remaining two years of his presidency.

"(Mugabe) has to accept that having lost the mandate of the people he cannot form the government, or he has to form it in consultation with the opposition," Tsvangirai, 48, said during a break from campaigning this week.

Tsvangirai has accused Mugabe, Zimbabwe's sole ruler since the former Rhodesia gained independence from Britain in 1980, of leading the country into economic and political crisis.

Tsvangirai and his party are tapping into voter anger over record unemployment of 50 percent, interest rates of about 70 percent and inflation of more than 50 percent.

Severe fuel and foreign currency shortages and a costly war in the Democratic Republic of the Congo have also worn down one of Africa's most promising economies.

Tsvangirai Arouses Strong Feelings

Tsvangirai, a fiery trade unionist who was elected MDC chief at the party's inaugural congress last year, has emerged as one of Zimbabwe's leading personalities in the past decade.

Those who love or hate him do so passionately.

To his admirers, Tsvangirai is a fearless nationalist putting his life on the line by challenging Mugabe's rule.

To ZANU-PF and its supporters, including mobs led by war veterans who have invaded hundreds of white-owned farms since February, Tsvangirai is being sponsored by Zimbabwe's former white rulers to undermine a black majority government.

"For a majority of our people, insults, slogans, labels and placards are not a substitute for substance," Tsvangirai said.

"For us in the MDC, they are just an irritation. Our emphasis is on policy, on detail, on what we propose to do when we get ZANU-PF out of government," he added.

But political observers say policy and detail is where the man who captivates the public with powerful speeches is weakest.

"At some of his meetings abroad, some of those he met found him on the shallow side in terms of policy and detail," one Western diplomat said. "We understand he did not impress."

Welshman Ncube, MDC secretary-general and a close Tsvangirai adviser, said his leader's visits to London and other European capitals earlier this year were not designed for detailed policy discussions, but to give foreign governments a broad overview of the country's political and economic problems.

Tsvangirai's lieutenants say he is an accomplished backroom organizer and consensus builder who united the Zimbabwe Congress of Trade Unions (ZCTU) against government efforts to split the labor movement.

Tsvangirai was elected ZCTU secretary-general 11 years ago, and is credited with charting an independent path for a movement Mugabe's government saw as an extension of the ruling party.

In 1998, Tsvangirai led national protests against tax and price increases. Mugabe sent in riot police and the army to crush what he saw as an attempted revolt.

Tsvangirai helped found the MDC last September. He was also instrumental in setting up the National Constitutional Assembly, a coalition of civic and opposition groups which this year defeated Mugabe in a referendum on extending his powers.

Tsvangirai was born in Zimbabwe's southern Buhera district and worked in a textile factory and later a nickel mine before became a union organizer. He is married with six children.