A British farmer who stood up to Robert Mugabe and was beaten, abducted and finally had his house burnt down has travelled to Washington to ask the Obama administration to put pressure on the Zimbabwe government before it seizes the last remaining white farms.

Ben Freeth, who moved to Zimbabwe from Kent, joined his father-in-law Mike Campbell in taking Mugabe to an international court to stop the farm seizures. Their secret footage of the campaign of intimidation launched against them will form part of a film to be released in London this month.

A Southern African Development Community (SADC) tribunal in Namibia ruled last November that the farm seizures were illegal and ordered Zimbabwe’s government to pay costs. Within a month President Robert Mugabe’s regime had sent thugs to set fire to both men’s farms while they were at church, destroying everything they owned as well as the homes of their workers.

In June the tribunal ruled that Zimbabwe was in contempt of court. Far from respecting the decision, a leaked document published in The Zimbabwe Times last week revealed that Mugabe plans to expel all the remaining white farmers and seize their land.

The land seizures were expected to stop when the former opposition leader Morgan Tsvangirai became prime minister last year after agreeing a peace deal with Mugabe. Tsvangirai, originally backed by white farmers, was even considered a candidate for this year’s Nobel peace prize.

Freeth said he had written four times to Tsvangirai but his letters were never acknowledged. Although the main levers of power such as the army, police and justice ministry have remained in Mugabe’s hands, Freeth insists that “Tsvangirai could at least be calling for action. He doesn’t seem interested in doing anything to get the rule of law respected”.

In desperation he decided to take his case to Washington. He spent Friday on Capitol Hill telling his story to legislators and hopes to meet Hillary Clinton, the secretary of state, this week.

“The United States is the biggest bilateral donor to Zimbabwe and it’s really important that they put pressure on the government to ensure the court judgment is respected,” he said.

Last year the United States provided $900m in humanitarian assistance to Zimbabwe, but Barack Obama has made clear his frustration at Mugabe remaining in power.

Freeth admits that time is running out. The leaked document states that no foreigner should be allowed to own rural agricultural land and warns that farmers who resist should be arrested.

“Land acquisition and redistribution is an ongoing process,” says a secret memorandum to cabinet issued by Herbert Murerwa, the lands minister, on August 27. “No foreigner should be allowed to own rural agricultural land in Zimbabwe.”

Only 400 white farmers out of an original 4,600 remain on their farms after a violent nine-year campaign to oust them. Instead of their land being distributed to the poor, much of it has gone to Mugabe’s relatives and cronies. Vast tracts of farmland now lie fallow and agricultural output has slumped.

The memo says there must be “no going back on farm seizures” and concludes that the prosecution of farmers refusing to move off the acquired land should be expedited.

“It makes a complete mockery of the global political agreement that committed parties in the unity government to the return to rule of law,” complained John Worsley-Worswick of the farmers’ lobby group, Justice for Agriculture.

“It shows the regime is planning to forge ahead with the so-called land reform programme even against everyone who has some protection.”

The revelation of the planned seizures came as the United Nations warned that Zimbabwe would grow only a quarter of the food it needed to feed its people, with the next maize harvest expected to fall by 70%. The country has faced acute food shortages since 2001 because of the destruction of the white-owned farms.

Mugabe has threatened to unleash the police on white commercial farmers who refuse to give up their land. He told the youth conference of his Zanu-PF party recently that the formation of the unity government between himself and Tsvangirai would not change the country’s stance on the land programme.

Farmers like the Freeths, who have resisted the seizures, have paid a heavy price. Their families and workers have endured relentless intimidation since 2004 when Nathan Shamuyarira, a Zanu-PF spokesman, arrived at the gate of their farm in Chegutu, 60 miles southwest of Harare, with an order telling them to hand it over to him.

When they refused they were arrested. Local wildlife was slaughtered, a safari lodge was burnt down and their mango crop was stolen.

Last year Freeth and his father-in-law were savagely beaten for seven hours, leaving Freeth, 40, concussed and with no sense of smell and 76-year-old Campbell with impaired memory.

In December Freeth, his wife Laura and their three young children returned from church to find their home in flames. “They had stolen all our tractors so we had no means of fighting the fire and they chose a day when the wind was blowing toward the house so it spread quickly,” Freeth said.

The local community rallied round, finding them a house in which to stay and donations of everything from pots and pans to school uniforms.

Freeth said it was difficult to describe the loss: “You feel so helpless, your whole history has been destroyed, all your photos, your children’s baby books, records of holidays, the kids’ toys.”

However, he is determined to rebuild. “I know there’s a threat we’ll finish it and they’ll take it over or burn it down over again. But it’s a road we started on a long time ago and to give up now would be a betrayal to our workers and the country as a whole.”

Mugabe and the White African will be shown at the London Film Festival on October21

Times Recommends

• African migrants desperate for a better life
• Karzai, the Anglophile who alienated the West
• They killed my family, but I rise again