The United States (US) has called for fresh elections in Zimbabwe in 24 months, labelling a unity government between President Robert Mugabe and Prime Minister Morgan Tsvangirai an “imperfect union” hampered by a power struggle between the erstwhile enemies.

US ambassador to Zimbabwe James McGee said little had changed politically in Zimbabwe despite formation of the unity government last month and said Washington would not yet lift targeted sanctions imposed on Mugabe and top officials of his old government and ZANU PF party.

The US and its Western allies – the source of the bulk of aid to Zimbabwe – have said they want Harare to submit a credible economic recovery programme, implement genuine and comprehensive political and economic reforms before they can lift sanctions and provide substantial financial support to the new government.

McGee, who described the political mood in Zimbabwe as “business as usual” – said the US wanted to see a new and democratic constitution in place in Zimbabwe in 18 months followed by free and fair vote to choose a new government.

“That is key – free and fair elections in Zimbabwe within 24 months would be an absolute key to anything that does happen positively in this country,” McGee said on Monday.

The US diplomat said the unity government had not made much headway since its formation on February 13 after months of power sharing negotiations facilitated by former South African President Thabo Mbeki on behalf of the Southern African Development Community (SADC).

Under pressure from SADC, Tsvangirai agreed to end his decade-long struggle to unseat Mugabe to take up the post of Prime Minister while his MDC party was allocated several ministerial posts including finance.

Arthur Mutambara, who heads a smaller formation of the MDC, was appointed Deputy Prime Minister with his faction also given some ministerial posts in an all inclusive government that immediately ignited hopes Zimbabwe could finally emerge from its crisis.

But McGee said a struggle for influence between Mugabe’s ZANU PF and Tsvangirai’s MDC parties was hindering progress and had left the unity government operating in “fits and starts”.

“We have two political parties occupying or attempting to occupy one government,” said McGee, in the most frank assessment of Zimbabwe’s unity government by a foreign diplomat to date.

“Each political party has a number of ministries that they control, a Prime Minister who is trying to exert his power, and then you have the President, Robert Mugabe, still trying to exert all of his power. So it is a very imperfect union right now,” McGee said.

The US envoy said farm invasions, blamed for destabilising Zimbabwe’s mainstay agricultural sector to plunge the country into endless food shortages, were still taking place, while at least 13 MDC activists continued to languish in prison.

“It is still business as usual, that is exactly what is happening, and we need to see some change,” said McGee. The US was “just not going to lift these sanctions” until Zimbabwe’s government showed it was committed to upholding human rights, he sad.

McGee, whose government has given Zimbabwe more than US$264 million in food and other humanitarian assistance since October 2007 and in recent months has provided more than US$6,8 million to fight cholera, said there had been some progress on health with the epidemic “somewhat under control”.

A cholera epidemic that began last August has infected more than 90 000 Zimbabweans and killed more than 4 000 others but the World Health Organisation that has led efforts to curb the disease said on Monday that there were signs the outbreak was coming under control with a drop in new infections and the death rate.