Harare  - Zimbabwe's parliament Thursday passed a constitutional amendment bill that clears some of the remaining hurdles to the formation of a unity government between President Robert Mugabe and the opposition next week.

The amendment creates the post of prime minister for Morgan Tsvangirai, leader of the opposition Movement for Democratic Change (MDC).

Tsvangirai is scheduled to be sworn in to the position on February 11. Under the terms of the power-sharing deal he signed with Mugabe last September, Zimbabwe's leader of 29 years remains president.

After being stalled for nearly five months by bickering between over how they would concretely share power, the MDC and Mugabe's Zanu-PF have committed to having the new government in place by February 13.

Introducing the bill in parliament, Justice Minister Patrick Chinamasa said it was actually a "miracle" that the amendment was finally before the legislature.

"It is been a long, bumpy and frustrating journey," he said, urging MPs and senators to let "bygones be bygones".

All 184 MPs present in the MDC-dominated 210-seat lower House of Assembly gave the bill the thumbs-up. The vote was also unanimous in the Senate. The amendment requires Mugabe's signature before becoming law.

MDC secretary general Tendai Biti described the vote as "historic." Referring to his own, known misgivings about the MDC sharing power with the authoritarian Mugabe, Biti asked: "Do we have any other choice?"

"Zimbabweans are suffering, dying or fleeing the country in their thousands. Let us give this experiment a chance."

At Tsvangirai's urging, the MDC last week gave in to pressure from Zimbabwe's southern African neighbours to go into government with Mugabe, despite the unity deal being heavily skewed in favour of Zanu-PF.

The MDC defeated Zanu-PF in last year's general election and Mugabe placed second to Tsvangirai in the last credible presidential election.

But the country's worsening humanitarian crisis has put pressure on the MDC to come onboard and help kickstart the country's revival.

A cholera epidemic has claimed close to 4,000 lives since August as basic service delivery, such as the provision of drinking water, judders to a halt for lack of state funding.

Over half the population of 11 million people is also in need of food aid as world-record inflation, estimated in the billions of percent, renders basic foodstuffs increasingly unaffordable.

Critics blame Mugabe's populist policies over the last decade of his 29-year rule for his country's ruin. Mugabe has in turn blamed the Western sanctions that target the ruling elite. (dpa)