US Republican presidential election candidate Mitt Romney has picked Congressman Paul Ryan as his vice presidential running mate.
The Wisconsin fiscal conservative chairs the US House of Representatives budget committee.
Mr Ryan, 42, is a favourite of the Tea Party, an anti-tax, limited-government movement that helped Republicans take over the House in 2010.
However, Mr Ryan's selection immediately draws attention to a budget plan he proposed as House budget chairman that would include controversial cuts in government health programs for the elderly and poor, Reuters reports.
Democrats are eager to pounce on that issue - particularly in Florida, where many seniors live and which could be a crucial state in the November election.
The announcement will mark the end of a months-long search by Mr Romney for a running mate to join him in facing Democratic President Barack Obama and Vice President Joe Biden in the 6 November election.
The former governor of Massachusetts is set to begin a four-day bus tour through key battleground states.
The trip campaign will visit the states of Virginia, North Carolina and Florida before finishing in Ohio.
In particular, Mr Romney will seek to fight back against the Democrats' push to portray him as upper-class and out-of-touch with ordinary Americans, observers say.
Recent opinion polls suggest a close race between the two men, with Mr Obama tending to have a slight lead in most surveys, the BBC reports.