Mr Mugabe is currently on a two-week tour abroad

Mr Mugabe invoked special presidential powers to give the authorities the right to impose stiff penalties on those who ignore the new edicts.

The move follows a series of one-day strikes called by the Zimbabwe Congress of Trade Unions, the ZCTU, which have brought the country to a halt.

Unions defiant

Under the new ban, those who organise such strikes are liable to three years in jail and $3000 fines. Employers can dismiss any worker who takes part in industrial action.

Union leaders say the new measures are almost certainly unconstitutional and insist they will continue to pursue their demands.

Initially, they called a series of one-day strikes to back their calls for a 20% pay rise for all workers and the reversal of a 65% increase in the price of fuel.

Correspondent Grant Ferrett in Harare say that after two such strikes failed to shift government policy, the unions have broadened the scope of their demands.

The ZCTU has called for:

• a reduction in the number of cabinet ministers, currently about 50
• the cutting back of the civil service
• more information about the cost of Zimbabwe's involvement in the war in the Democratic Republic of Congo