Football fans who watch the televised English Premier League match between Stoke City and West Ham United on Saturday may get an urge to visit Tanzania. Adverts in Stoke's Britannia Stadium will tout the country's attractions, including the Serengeti National Park.

Home to an iconic wildebeest migration, the Serengeti is one of the most valuable ecosystems on the planet. So why does President Jakaya Kikwete of Tanzania want to build a road through it?

In an Opinion piece on page 272, 27 conservation experts warn that the proposed road could drive the entire Serengeti ecosystem to collapse by interrupting or diverting migration routes. No more wildebeest migration. No more tourists. The consequences seem dire.

Plans for a road across the Serengeti have been rejected on environmental grounds before. The World Bank refused funds in the 1980s, and impact assessments by external consultants in the 1990s found that the probable damage was too high a price for transport convenience.

Yet, in late July, Kikwete confirmed that his government would send bulldozers to the Serengeti in 2012, repeating a campaign pledge that he made in 2005. Markers along parts of the proposed route are already in place.

The president's desire to push the road through the Serengeti is especially puzzling given that an alternative route, farther south and outside the boundaries of the park, would bring many of the same economic benefits from increased trade and avoid the most serious effects.

As the New York Times noted last month, Kikwete's government is not keen for anyone to pursue its reasoning — especially Tanzanians.

Conservation and politics are tightly bound, and in this case the politics are opaque indeed. Ahead of coming elections in the country, there are rumours of favours to be repaid to the communities in the north and east of the Serengeti that would benefit the most from the road.

Some observers claim that the Chinese government is set to fund the US$480 million project, to help extract raw materials such as minerals from its existing investments in east Africa. There has been no official explanation of the reasons for the decision or of where funds will come from. It is difficult for anyone outside the Tanzanian government to know anything for sure.

Against this uncertain background, those pushing for the Serengeti road to be abandoned should proceed with caution to avoid exacerbating the situation. Thousands of people across the world have backed protest websites, and some in the US tourist industry mutter about a possible boycott of Tanzania — leading Kikwete to hit out at what he characterizes as pressure from ill-informed foreigners.

A swell of well meaning but poorly targeted international criticism could strengthen the president's position and allow him to promote the road as a way for Tanzania to stand up to meddling outsiders.

Critics should also be careful not to overstate the case. The government has so far promised only a gravel road; predictions of the most serious ecological damage are based on an upgraded tarmac highway protected with fences, which would probably follow.

The next step should be a comprehensive and independent assessment of the two routes and their respective merits. If the southern route proves as superior as its supporters promise, then those both outside and inside the Kikwete government will be able to present it as the wise environmental and political choice. That is the best way to stop the road taking this damaging and unnecessary route.