Kuwaiti opposition candidates were expected to make gains in a snap parliamentary election being held on Thursday in the oil-exporting Gulf Arab state.

Kuwait's ruler, Sheikh Sabah al-Ahmad al-Sabah, called the vote in December after dissolving the chamber in response to a deepening political deadlock that has stymied reform and held up vital development projects.

In the past years the parliament broke our hearts and let us down, said Badr Yousef al-Juweihel after casting his ballot at al-Adeyliya polling station in central Kuwait. We didn't benefit, in fact we went backwards and our time was wasted.

Frustration has been growing at the impasse which came to a head in November when protesters led by opposition MPs stormed the assembly demanding the resignation of then-Prime Minister Sheikh Nasser al-Mohammed al-Sabah, accusing him of corruption.

The vote, in which 287 candidates are competing for seats, will usher in Kuwait's fourth parliament in six years.

The situation cannot remain as it was, opposition candidate Faisel al-Mislem told hundreds of supporters at a campaign event in the run-up to the election. If this election is just a game of musical chairs then it's a waste of time.

Kuwait's parliament is fully elected with legislative powers, unique in a region ruled by autocrats who tolerate little dissent. But formal political parties are not allowed, which means opposition politicians are forced to rely on forming blocs in parliament.

That has undermined the ability of parliamentarians to mount effective opposition with clear programmes.

Shahin Shamsabadi, senior associate at the Risk Advisory group, said deputies still had a chance of broadening the powers of the 50-member chamber if public opinion were on their side.

The key thing is: are the people going to be fed up enough this time to change the parliament, or is it going to take another election? Shamsabadi said.

VOTE FOR DEVELOPMENT

Men and women queued outside separate schools, handing their identity cards to a panel before selecting up to four candidates on a piece of paper and slipping it into a see-through ballot box.

I voted for the people who will accelerate development and the economy, said Monia al-Nouri, emerging from a polling station in a suburb of the capital.

We have many Kuwaitis who don't have job opportunities. Things are dead in the water now in terms of the economy and social development.

Tempers have flared before the vote. Tribesmen torched the tent of a candidate who appeared to insult their tribe and skirmished with police outside the office of a satellite channel that was hosting his ally.

Other candidates have been coaxing voters into their tents with lavish buffets and pledges ranging from lifting a ban on the sale of alcohol to bringing laws into line with Islam.

Youth groups armed with smart phones and access to social networks have been organising their own campaigns.

We need to move on and I think people are seeing that and are moving towards that, said blogger Jassim al-Qamis, member of a team organising liberal ex-MP Aseel al-Awadhi's campaign.

Opposition players accuse the government of misdeeds and corruption ranging from bribery, turning a blind eye to diesel smuggling and fomenting divisions within parliament.

Politicians say their battle will continue and few expect this election to end the antagonism.

These elections have shown the government's true cards. It continues to play the same tawdry game, said opposition ex-MP Jamaan al-Hirbish.

Although parliament has the power to initiate legislation, cabinet members also vote, giving the government a bloc it can use to dilute opposition or swing a majority in the assembly.

And crucially, reforms depend on the will of the al-Sabah family which has ruled Kuwait since the 18th century.

Meaningful constitutional reform is unlikely under the leadership of the current emir, said Jamie Ingram, an analyst at RUSI based in Qatar. However after power transitions to a new generation, more deep-seated change is likely.

(Writing by Isabel Coles; Editing by Sami Aboudi and Maria Golovnina)

(Corrects first paragraph to refer to candidates)