By BBC News Online's Russell Smith

The rejection by Zimbabwean voters of a new constitution is a major blow for President Robert Mugabe and his 20-year-old government.

The president invested a lot of his authority in achieving a yes vote and failed.

Opposition figures are now warning that the government will also lose elections due in April.

The proposed constitution was intended by the government to consolidate presidential powers and allow the government of Zimbabwe to confiscate white-owned land for redistribution to black farmers without compensation.

And the failure of the government to attract sufficient numbers to vote with them is a signal of how far support for the 75-year-old president has eroded.

Many see the former guerrilla leader as increasingly autocratic and out of touch with ordinary Zimbabweans.

And his outspoken comments on gays and Western aid have done him no diplomatic favours.

Economic mess

However, probably the most significant issue is the high level of dissatisfaction at the government's handling of the economy.

When Robert Mugabe took over as Zimbabwean prime minister, following the first genuine multi-party elections in 1980, he inherited a prosperous economy and a well-developed infrastructure, albeit one that had been geared to serving the white minority.

The legacy of a thriving agricultural and industrial base has been squandered.

Zimbabwe's economy is now a mess.

Fuel and power shortages are crippling business.

Health and education services are collapsing with strikes increasingly frequent, and inflation and unemployment are at record levels.

And there is little immediate prospect of improvement. The IMF and other donors have withdrawn financial support and hardly any new jobs are being created, while every year, hundreds of thousands of school-leavers enter the labour market.

And in the middle of Zimbabwe's worst economic crisis since independence in 1980, President Mugabe's government is reported to be spending millions of dollars each month on a war not even on its own doorstep.

Unpopular war

An estimated 11,000 Zimbabwean soldiers form the mainstay of support for Democratic Republic of Congo President Laurent Kabila's government in his war against rebels backed by Rwanda and Uganda.

Zimbabwe's expensive involvement in the Democratic Republic of Congo continues despite opposition at home and no obvious strategic advantage.

Critics suggest the only motivation is that of financial gain for individuals connected to the army and government - in other words, corruption.

A new opposition party has emerged recently promising more competent and less corrupt economic management.

And for the first time since independence they could mount a serious challenge to the ruling Zanu-PF party.

UK Government minister Peter Hain has warned that Zimbabwe is facing financial ruin and is on the brink of an abyss.

But as with many issues, President Mugabe is unlikely to see it that way.