* Opposition says vote changes favour pro-government candidates
* Party atmosphere at demonstration on edge of capital
* Latest stand-off follows years of political deadlock (Adds end of march, details)
By Sylvia Westall
KUWAIT, Dec 8 Tens of thousands of Kuwaitis marched in the capital on Saturday in a peaceful protest against a parliament elected last week in the Gulf Arab state under voting rules deemed unfair by the opposition.
Rule changes passed by an emergency decree in October, which reduced the number of votes per citizen to one from four, have prompted a spate of mass demonstrations and led the opposition to boycott the Dec. 1 election.
The government, in which members of the ruling family hold top posts, says the new rules bring Kuwait into line with democratic norms elsewhere. The opposition, which includes Islamist and populist politicians, says the changes were designed to skew polls in favour of pro-government candidates.
Crowds of men, women and children wearing orange, the colour of the protest movement, marched along a coast road on the edge of Kuwait City, heading for Kuwait Towers, a major landmark by the Gulf.
Holding Kuwaiti and orange flags, they chanted: "The people want to bring down the decree!"
Singing and clapping, some flashed four fingers - the number of votes under the old system - at a police helicopter circling above.
Parents took pictures of children holding up protest signs and balloons during the march which dispersed peacefully after around one and-a-half hours.
Years of political turmoil have held up investment and economic reforms in Kuwait, a U.S. ally and OPEC member state which has held five parliamentary elections since mid-2006.
The protesters say they want wider political reforms but not an Arab Spring-style revolution.
"We reject the last election because of the one vote system, because most of the people did not participate," 21-year-old student Saad al-Zobi said.
"We want the four-vote system back and new elections," he said as people in traditional Kuwaiti robes and headscarves and others in orange T-shirts and jeans milled around.
Ruler Sheikh Sabah al-Ahmad al-Sabah has said his amendments will help preserve national security and stability.
"THE PEOPLE SHOULD BE CONSULTED"
Under the old system, politicians could urge supporters to cast additional ballots for like-minded candidates - a way to build informal alliances in a country where parties are banned.
"We, the people, should be consulted when there are any big changes," Nadja Saleh, a 45-year-old bank worker said, gesturing at the crowd. Slogans carried on large orange banners read "Justice, liberty and equality" and "Dictatorship is destructive, democracy is constructive."
Police had put up some barricades along the march route but their presence appeared light. Other recent marches, which authorities said were unlicensed, have been broken up using tear gas and smoke bombs.
"We are against the result of the elections. The new parliament does not represent us," 26-year-old government official Nadam Mohammed said.
The new parliament is expected to be more government-friendly than its predecessor. It was elected on a 40.3 percent turnout according to government-cited figures, the lowest ever Kuwait's electoral history.
The opposition held a majority in the last assembly elected in February and put pressure on the cabinet, forcing two ministers out of office.
Kuwait has the most open political system among the Gulf Arab states. Parliament has legislative powers and the right to question ministers.
But the emir, head of the Al-Sabah family that has ruled Kuwait for 250 years, appoints the prime minister, who chooses the cabinet.
The government says opposition lawmakers have used parliament to settle scores rather than pass laws to develop the economy. Opposition politicians accuse the government of mismanagement and have called for an elected cabinet. (Editing by Sophie Hares)