HARARE (Reuters) - Zimbabwean Prime Minister Morgan Tsvangirai on Monday ruled out foul play as the cause of a car crash that injured him and killed his wife, easing concerns that it would increase tensions in the new government.

Tsvangirai must cope with his grief alongside the enormous pressure of trying to rescue the shattered economy in a new unity government with President Robert Mugabe, his old rival.

In such incidents there is always speculation, but in this case I want to assure you that if there was any foul play it would probably be one in 1,000, he told mourners for his wife after returning home from medical treatment in Botswana.

It was an accident which unfortunately took a life. I am sure that life has to go on and I'm sure she would have liked for life to go on, he said.

Many Zimbabweans are suspicious about Friday's crash on a dangerous potholed highway, neglected like many others during the country's economic decline.

The driver of the truck that slammed into Tsvangirai's vehicle and forced it to roll off the road appeared at a court in Chivhu, 150 km (around 90 miles) south of Harare, on Monday, accompanied by three plain-clothed policemen.

Chinoona Mwanda's application for bail was granted and he was remanded to return to court on March 23, said his lawyer Chris Mhike.

He's (Mwanda) quite distressed, he's yet to come to grips with the reality that life was lost, Mhike told reporters.

MOURN WITH HOPE

Tsvangirai's wife of 31 years, a pillar of strength during 10 often trying years of opposition to Mugabe, is expected to be buried on Wednesday.

It will be difficult to fill in the gap. We have gone through trials and tribulations together, I know it's painful, but let's mourn with hope, said Tsvangirai, his face swollen from injuries sustained in the crash.

Questions may arise over how quickly Tsvangirai can recover from the loss and get down to tackling an economic meltdown that has brought 90 percent unemployment, hyperinflation and shortages of basic foods and fuel.

I don't think this will have any significant impact on the inclusive government and how he operates in it, except that the MDC should now demand higher security for the prime minister, said political commentator and Mugabe critic John Makumbe.

Mugabe's ZANU-PF and Tsvangirai's MDC signed a power-sharing deal in September and formed a government after months of wrangling.

Tsvangirai must find a way to work with Mugabe and win over Western donors who insist on democracy and economic reforms in Zimbabwe before providing aid. The arrest of activists and other issues have created friction between them.

Apart from the tragedy itself, I am worried about Tsvangirai's own emotional and mental state. The country needs him badly, said Tonderai Chari, an office worker.

Who knows? Some good might come out of this, after all, the president (Mugabe) visiting Tsvangirai in hospital might be the beginning of better relations, despite these sad circumstances.

(Editing by Kevin Liffey)