Southern Africa is facing massive problems as a result of the crisis in Zimbabwe, the foreign secretary has told the Commons.

Ahead of a Commons debate on the deteriorating situation in Zimbabwe, Jack Straw condemned the actions of Robert Mugabe.

Straw said that the ruling Zanu PF party's decision to demand that the country's farmers stop work was "extraordinary and destructive".

"Zimbabwe's only way back from disaster is through the restoration of the rule of law, an end to political violence, an end to the intimidation and arrest of journalists, a return to democratic legitimacy and the adoption of credible economic policies,'' he said.

He said the country was experiencing "a man made tragedy" brought about by Mugabe's regime. A country that is naturally rich was now only able to produce 850,000 tons of food as a result of the measures imposed by the Zimbabwean government, Straw said.

"We condemn the extraordinary and reprehensible decision of Zanu PF to order farmers in Zimbabwe to stop farming and to drive them and their workers off the land at a time when the people of Zimbabwe face a level of starvation unparalleled in their recent history," he told MPs.

Straw revealed that land seized by Zanu PF had not been handed over to ordinary farmers. Most had gone to 10 cabinet ministers, seven MPs and Mugabe's brother-in-law.

Sanctions against Zimbabwe were proving effective, Straw assured MPs.

For the Conservatives, shadow foreign secretary, Michael Ancram, asked what the government was doing to change the situation. He questioned whether the travel ban on Mugabe and his associates was working.

"Does he really believe that his henchmen are experiencing the isolation that was intended?" he said.

Menzies Campbell, the Liberal Democrat foreign affairs spokesman, described events in Zimbabwe as "truly the theatre of the absurd".

Inflation was running at 112 per cent, unemployment had reached two thirds, foreign investment had fallen to $4 million and half-a-million people had died from HIV, he said.

"It's fair to describe the country that is under the threat of Mugabe as a country in free-fall," he said.

Foreign Office minister Denis MacShane described the situation as "lamentable". The minister said that he hoped the people of South Africa would "one day rise up" against Mugabe's regime.

Conservative backbencher Sir Nicholas Winterton asked whether Britain had called on former South African president Nelson Mandela to get involved.

"I think the people of Zimbabwe would be delighted if Nelson Mandela took a direct personal interest. Whether Mugabe would listen to him is another matter," said MacShane.