The move has been taken to gain wider international support for fresh elections and human rights reform in the face of intense pressure on the party and the media by the Zimbabwean government.
London-based agency Chelgate has been hired by MDC and a group of unnamed individual backers to handle the campaign, called Save Zimbabwe.
Target audiences are the United Nations, European Union and the African Union, the successor body of the Organisation of African Unity. Global aid agencies are also being lobbied.
Chelgate chairman Terence Fane-Saunders leads the account, reporting to MDC leader Morgan Tsvangirai.
Chelgate is to use affiliate agencies in Germany, Washington and South Africa.
The immediate aims of the campaign are for human rights reforms and a suspension of farm-land seizures.
Politically the MDC appears to be in limbo after losing the national election earlier this year, a result the party still disputes. Also, Tsvangirai could face jail after being accused of treason. He is currently on bail following the emergence of a videotape allegedly showing him plotting the downfall and possible assassination of president Robert Mugabe.
Tough media restrictions are in place, with critical journalists facing prosecution and expensive licences to operate. Guardian correspondent Andrew Meldrum was acquitted of the charge of reporting a falsehood this week.
In a statement released by Chelgate, Tsvangirai said: 'The policies of this government have shattered the economy. Soon it will be too late to reverse the damage; the destruction will be beyond repair.'
The spokesman for the Zimbabwean High Commission in London was unavailable for comment.