U.S. voters will cast their ballots to elect the 435 members of the House of Representatives and one-third of the 100 Senate members on Tuesday in the 2006 midterm elections.

The following is some background information about the midterm elections.

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 will be elected, as well as state legislators 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.

House members are elected for two-year terms. In the current 109th Congress, there are presently 229 Republican members, 201 Democrats, one Independent and four vacancies in House of Representatives.

All 435 seats in the House are up for election. Democrats need a net gain of 15 seats to recapture control of the House in this year's elections, after they have been in the minority for the past 12 years.

In the Senate, members are elected for six-year terms, with one third of the seats up for a vote every two years. Currently, the Republican Party holds a majority of 55 seats against the Democrats' 44 seats, and there is one Democratic-leaning Independent. Of those 33 seats up for election, 17 are held by Democrats, 15 by Republicans and one by Independents. Democrats need to get six more seats than their current number to take control of the Senate.

Of the 50 U.S. states, 34 will elect their governors for four-year terms during the midterm elections, and two states -- Vermont and New Hampshire -- elect governors for two-year terms. State and local elections will also be held on Tuesday, to elect officials for state legislatures, and city and county offices.