Voting is continuing in the mid-term elections in the United States.
All 435 seats in the House of Representatives as well as a third of the seats in the Senate are at stake.
Polling stations in eastern US states opened at 6am (11am Irish time) and are due to close at 6pm local time, but it could be hours before results in the tightest contests are known.
President Goerge W Bush was an early voter in Texas and urged everyone with a vote to cast their ballot.
Voting will end in the last stations to close, those in Alaska, at 5am Irish time tomorrow.
There have already been problems with electronic voting machines in a number of states, including Ohio, Maryland, New York, Pennsylvania and Florida.
In one polling station in East Cleveland, Ohio, all 12 machines went down when voting opened.
The machines were not started up until two hours later and officials refused to hand out paper ballots until a lawyer for the watchdog group Election Protection showed up.
Problems were also reported at other polling places in the state, which was involved in controversy over the results of the 2004 elections.
Republicans set to lose seats
There are indications that the Republican Party may lose control of both houses of Congress, although there are also reports of a late surge in support for the ruling party.
Democrats need a net gain of 15 seats to recapture the House of Representatives for the first time since 1994, and six seats to take control of the Senate.
Much Democratic campaigning has focused on the Iraq policies of US President George W Bush.
Last night, Mr Bush made a final appeal for votes in an attempt to boost support for the Republicans. Speaking in Arkansas, Mr Bush said his party would win because it had the right policies on tax and security.
Mr Bush had spent the last day of campaigning in Florida and Arkansas before returning to his ranch in Crawford, Texas, last night.
Mr Bush and his advisors were confidently predicting that the last-minute poll boost would translate into votes.
Iraq policies highlighted
Democrats, who hope to win control of at least one of the Houses of Congress, are saying Republicans have blindly followed what they term Mr Bush's failed policy.
The chairman of its National Committee, Howard Dean, ended the party's campaign by telling voters that if they wanted a change in direction on policy towards Iraq, they should vote Democrat.
The vote is one of the most closely fought mid-term elections of recent years.
Political analysts have predicted the Democrats will take back the majority in the House but may not be able to win the Senate.
Opinion polls suggest a Democrat gain of at least two Senate seats, Ohio and Pennsylvania, with control of the upper chamber hinging on the tight races in Virginia, Rhode Island, Missouri and Montana.
Some 200 million US citizens are eligible to vote.
