Members of the Republican majority in the United States congress are voting to choose the new Speaker of the House of Representatives -- one of the most powerful positions in American politics.

They are expected to choose Dennis Hastert, a little-known congressman from the state of Illinois.

The position became vacant after the resignation of the outgoing speaker, Newt Gingrich, following the Republican Party's poor showing in the November congressional elections and the announcement last month by Mr Gingrich's expected successor, Bob Livingston of Louisiana, that he had had extramarital affairs and would not seek the speakership.