Ugandan opposition threatens to block 2011 poll

* Main Ugandan opposition party threatens chaos, violence

* Opposition party demands changes in election body

By Elias Biryabarema

KAMPALA, June 9 (Reuters) - Uganda's main opposition leader threatened on Wednesday to bring chaos and violence to the country in order to block elections meant for early next year unless the election commission (EC) is revamped.

The east African country, which should start producing oil in 2011, is due to hold elections in February but tensions are mounting over the independence of the body overseeing the poll. The last polls in 2006 were disrupted by violence.

"We insist that we must have a free and fair election and that cannot happen with the current EC," Kizza Besigye, president of the Forum for Democratic Change (FDC) party, told Reuters in Kampala on Wednesday.

"So instead of allowing this partisan EC to hold the election (and there be) chaos after, we shall have the chaos now. We won't allow the election to take place," he said.

The opposition complains that the EC leadership is biased in favour of President Yoweri Museveni and his National Resistance Movement (NRM) party, which has been in power since 1986. Museveni will be standing for a fourth term in power.

After the last two polls, Supreme Court judges said the election body had failed to uphold the law in running the polls, but Museveni's victories have not been overturned.

Besigye is likely to be picked as a joint candidate for the opposition coalition Inter-Party Cooperation (IPC), which brings together all but one of Museveni's rivals. He was arrested in the run up to the last polls, in which he came second.

"We shall mobilise all citizens to assert their rights and we shall have as much violence as the government wants until they accept to implement our electoral reforms," he said, after a minor opposition rally was dispersed in the capital.

INVESTMENT IN OIL

Besigye, who was once Museveni's doctor but fell out with the former bush fighter, said opposition leaders would carry out a series of unspecified activities across the country to block the election unless the election commission was revamped.

Museveni was initially credited with returning stability and economic vitality to Uganda after years of brutal dictatorship and civil wars in the 1970s and early 1980s. Firms like Tullow Oil (TLW.L) have invested hundreds of millions of dollars in the country's western Lake Albert oil blocks.

However, several Western donors and international civil society organisations now accuse him of suppressing the opposition and free speech, strengthening his grip on power and failing to rein in rampant corruption.

Last year Museveni rejected objections by the opposition and democracy pressure groups and reappointed top EC officials.

A report to the U.S. Congress in April by the Secretary of State Hillary Clinton said Museveni's unilateral decision had eroded the independence of the electoral body. (Writing by David Lewis; Editing by Charles Dick)