Thousands of Zimbabwe's white farmers must decide by midnight tonight whether to fight President Robert Mugabe's government and risk jail or to flee lands they have farmed for generations.

Bringing his programme to reclaim land occupied by white settlers up to 112 years ago to a crescendo, Mugabe has given nearly 3,000 of the country's 4,500 white farmers a Thursday deadline to hand over their land for occupation by blacks.

Under a land seizure law, a farmer who defies an eviction order faces a fine and up to two years in prison.

The farmers are the first major group to face eviction since Mugabe launched his drive to compulsorily acquire white-owned farms for black resettlement two years ago.

On Wednesday, Zimbabwe state radio quoted Mugabe as saying in Singapore that he was determined to press ahead with his land reforms, despite allegations he was wrecking the country's farm-based economy.

"President Mugabe said that the fast-track resettlement programme is now over and the government is now concentrating on making the new farmers productive," it said, but made no mention of the eviction deadline.

Zimbabwe government officials refused to comment on the issue on Wednesday.

They said Joseph Msika, acting president while Mugabe is abroad, would make a statement "at an appropriate time". Some sources said he was likely to reaffirm the government's drive.

The majority of Zimbabwe's 4,500 white commercial farmers are of British origin. Their families have lived off the land throughout the past century, helping to build what was until recently one of Africa's strongest economies.

Commercial agriculture, dominated by tobacco, is the mainstay of Zimbabwe's economy, and analysts say its disruption through state-backed farm invasions has compounded food shortages and a severe economic crisis blamed on government mismanagement.

But Mugabe, Zimbabwe's sole ruler since the former Rhodesia gained independence in 1980, says his land seizures are meant to correct the wrongs of British colonialism which left 70 percent of the country's best farmland in white hands.

The 78-year-old president says he plans to complete his "fast-track land resettlement programme" by the end of August.

NINETY DAYS TO QUIT

In May, Mugabe signed a law giving 2,900 farmers 45 days to wind up their operations and another 45 days -- expiring at midnight on August 8 -- to move off their land and make way for black settlers.

Some of the farmers say they will go. Others say they will defy the land acquisition and eviction orders and fight both through the courts.

White farmers' leaders have been working feverishly behind closed doors to win an extension of the deadline, but government sources say the chances of a reprieve are slim.

Mugabe, forbidden under Western sanctions to set foot in the United States or any European Union country, is on a business trip in Asia and Agriculture Minister Joseph Made is away in Iran.

But Local Government Minister Ignatius Chombo -- who chairs the government's land acquisition audit committee -- warned on Tuesday that any farmer who defied the government's eviction orders would face the "full wrath of the law".

Zimbabwe has been in crisis since February 2000, when pro-government militants, led by veterans of the 1970s liberation war, began invading white-owned farms.

Eleven white farmers have been killed during the farm invasions, and thousands of black workers have been assaulted and forced to abandon farms.

The Commercial Farmers Union (CFU), which represents the white farmers, says it supports land redistribution, but is opposed to the system employed by the government.

CFU members were meeting for an annual congress on Wednesday likely to focus on the looming evictions.

The CFU has so far made no statement on the deadline, but a new splinter group advocating legal challenges against the government is urging farmers to fight on.

"Our position is that people should not give in because we are in a crisis as a country," Justice for Agriculture (JAG) chairman David Connolly told reporters.

Zimbabwe, usually a grain exporter, is facing a severe food shortage caused by the farm disruptions coupled with drought.

The European Union and the United States have imposed sanctions on Mugabe and his ruling elite over his land policy and after his controversial re-election as president in March.

Many Western powers say the election was rigged and are backing demands by the main opposition Movement for Democratic Change (MDC) for a fresh poll.

Mugabe insists he won fairly, and dismisses calls for a rerun as attempts to impose MDC leader Morgan Tsvangirai as leader of the southern African country.