THIMPHU, Bhutan (AFP) - Bhutan begins its second ever parliamentary election on Friday, after polling officials trekked for up to seven days to reach voters in the most remote corners of the Himalayan kingdom.

While the electorate comprises fewer than 400,000 people, voting is a huge logistical challenge across the rugged terrain, where democracy was ushered in just five years ago after Bhutan's "dragon kings" ceded absolute power.

Armed with satellite phones to send in results, polling staff have braved heavy rains and slippery leech-infested trails to ensure that even isolated yak-owning nomads can cast their vote, the national Kuensel newspaper reported.

"Because the monsoon period has started people may face a little difficulty in climbing the mountains ... but as of now all are set and ready," Mr Sherab Zangpo, a spokesman for the Election Commission of Bhutan, told AFP.

Voters will choose from four parties in Friday's primary round of voting for the lower house of parliament, the National Assembly.

The two most popular parties will then contest a run-off round on July 13 to form the next government of Bhutan, a nation renowned for prioritising "Gross National Happiness" over economic growth.

In the country's first election in 2008, the centre-right Druk Phuensum Tshogpa (DPT) won a huge landslide and secured 45 of 47 seats available against the People's Democratic Party.

This time, two new centre-left parties are joining the contest, both led by women, but the DPT is generally expected to win again through its popularity with rural communities, which make up about 70 per cent of the population.

In the past five years, they have seen hugely improved access to roads, electricity and mobile phone networks. But many educated, urban voters are less impressed with the government's work, said political analyst Kencho Wangdi.

Their concerns include a string of corruption scandals, a lack of new jobs, a weak private sector and a rupee liquidity crunch.

Bhutan is heavily dependent on its neighbour India for aid, investment and imports, and too much demand caused stocks of the Indian rupee to run out last year. Bank loans and imports of cars and luxury goods are still banned in Bhutan as a result.

Despite urban people's frustrations, they are likely to hold less sway over rural voters than they did in 2008 when the country somewhat reluctantly embraced democracy on the command of the revered monarch, Mr Wangdi said.

"Now after five years... the sense is that they can make up their own mind. They know a fair amount about what democracy is and who to vote for, and they're saying that they will vote based on informed choices."

There was little sign in the capital Thimphu of election fever a day ahead of the polls, owing to a 48-hour campaign blackout and strict rules on election posters, but many began setting off for their family homes to vote.

Turnout was just 45 per cent in an election last month for the upper house of parliament, the National Council, but greater interest is expected on Friday, which has been declared a public holiday.

In a bid to boost turnout, officials have been broadcasting footage of the fifth dragon king, Jigme Khesar Namgyel Wangchuck, encouraging people to vote.

"One word (from him) is more effective than a collective effort from the people," said Mr Zangpo.