By Joseph Winter BBC News Online

Tents were originally set up in oases during camel trips across this country on the edge of the Sahara desert, but they are now put up on waste ground in urban areas, even if the sand is still blown in by the wind.

President Ould Taya enjoys the advantages of incumbency

In between political speeches, loudspeakers blast out the music of the divas associated with each party.

The presidential election is not expected to lead to a change of power but there are two significant firsts, reflecting the slow transformation of Mauritanian society.

Aicha Mint Jeddane becomes the first woman to run for president, not just in Mauritania but across the Arab world.

And Messaoud Ould Boulkheir will become the first descendent of slaves to seek Mauritania's top job.

His Action for Change party, along with human rights groups, says that slavery is still practised 22 years after it was first outlawed.

Islamic Republic

Whether or not some people are unable to leave their masters is difficult to ascertain, but the dark-skinned descendents of slaves, or Haratin, who have adopted most aspects of Moorish culture, remain a large underclass.

With low education rates, many Haratin may be unaware that slavery has been abolished, or may not wish to take the risk of venturing out on their own away from the life they know.

MAURITANIA Dominated by light-skinned Arabic-speakers (Moors) Campaigners say slavery still practised Black Africans complain of discrimination Mostly Sahara desert Islamic Republic Recognises Israel

Light-skinned, Arabic-speaking Moors have always held the reins of power, while in the south, along the fertile River Senegal, live people who speak West African languages and are culturally closer to the inhabitants of Senegal and Mali.

But all three groups are united by their Muslim faith and Mauritania is officially an Islamic Republic.

This has led to some trouble for President Mouaaiya Ould Taya, who has been criticised for abandoning his support for Saddam Hussein long before he was deposed, moving closer to the West and opening diplomatic relations with Israel.

In June, some sections of the army tried to mount a coup, partly fuelled by opposition to Mr Taya's pro-western stance.

The coup was put down after two days of bloody fighting in the capital, Nouakchott, but it was a reminder that in Mauritania, any change of power has historically resulted from military action, rather than the ballot box.

Family affair

Mauritania has a population of just 2.8m and especially among the elite Moorish circles, everyone seems to know everyone else.

Since independence from France in 1960, three families have vied for power.

Mr Taya seized power in 1984 from the man who is expected to mount the strongest challenge, Mohamed Khouna Ould Haidallah.

Mauritanians still retain their nomadic traditions

Mr Haidalla, working with Mr Taya, had in turn used force six years earlier to oust the country's first president, Moktar Ould Daddah, who died last month.

The outpouring of national mourning might help his half-brother, Ahmed Ould Daddah, a long-time opponent of Mr Taya, who has been arrested on several occasions.

The opposition claim they are the victims of state oppression and say the vote is unlikely to be free and fair.

They say Mr Taya uses the state machinery in his campaign and the opposition are excluded from state media.

Women's rights

The 1992 election had major irregularities, with all soldiers under strict orders to vote for Mr Taya and his Democratic and Social Republican Party.

As a result, most opposition parties boycotted the 1997 poll but the authorities say this time will be different, after the introduction of photograph voter cards.

But their decision not to invite foreign observers this time round will do little to dispel the doubts about the transparency of the poll.

The opposition say they are not free to campaign

The authorities accuse the opposition of planning to stage a coup if it loses the vote and arrested Mr Haidalla on the eve of the election.

Aicha Mint Jeddane become the first women to seek to become Mauritania's president and says she is fighting for women's rights.

That she is running is undoubtedly a step forward for Mauritania's women, although they do enjoy more social freedom than in many Arabic societies.

But she is not expected to win many votes and is unable to read or write, reflecting some of the obstacles to turning Mauritania from a society of camel-herding, slave-owning nomads into a modern, pluralistic society.