Voters across the United States will go to the polls on Tuesday, to elect all 435 members of the House of Representatives and one-third of the 100 Senate members, in the 2006 midterm elections believed to be crucial for both of the two major parties.

Polling stations normally open at six or seven in the morning local time, and preliminary results will be announced as early as Tuesday evening.

Plagued by the ongoing violence in Iraq and a series of scandals, Republicans have had lower public support than their Democratic counterparts. Recent polls and political analysts predicted that the Democratic Party was highly likely to gain control of the House, and House Minority Leader Nancy Pelosi, from California, would become the first woman speaker in U.S. history.

All 435 seats in the House are up for election for two-year terms. Democrats need a net gain of 15 seats to capture control of the House, after being in the minority for the past 12 years.

In the Senate, the Republican Party currently holds a majority of 55 seats against the Democrats' 44, and there is one Democratic-leaning Independent. Democrats need to get six more seats than their current number to retake control of the Senate.

Most political pundits in Washington forecasted that the Democrats would increase their number of seats in the Senate, and that the toss-up elections in a number of states, including Virginia, Missouri and Montana, could decide which party controlled the Senate in the next two years.

The 110th Congress, consisting of lawmakers elected this year and two-thirds of the Senate members not up for election in 2006, will be sworn in in early January 2007.

The United States holds federal elections on the first Tuesday after the first Monday in November of every even-numbered year, in which all House members and 33 or 34 of the 100 Senate members are elected, as well state legislatures and some state governors.

While presidential elections take place every four years, those elections for Congress that do not coincide with presidential races and occur midway through a presidential term are called midterm elections.

Also on Tuesday, gubernatorial elections are to take place in 36 states, as well as state and local elections to elect officials for state legislatures, and city and county offices.

Editor: Yan