With the 2008 US presidential election heading into the home stretch following the Democratic Party convention in Denver and the selection of vice-presidential candidates, the Obama-Biden ticket is firming in odds favoritism.

Barack Obama is a 1/2 favorite at UK bookmaker Ladbrokes to become the first black man to make it to the White House. The ticket of John McCain and Sarah Palin is 6/4 to make it 12 years of unbroken Republican rule at the executive level.

Obama enjoyed a boost on the back of the party's convention in Denver last week, with two separate opinion polls recorded Monday showing he has a healthy lead over his rival. A US Today poll gave Obama 50% support among registered voters, compared to 43% for McCain. A CBS poll had Obama at 48%, up against his opponent's 40%.

But McCain can enjoy his own "bounce" in the polls if the Republican national convention, which began Monday in Minneapolis-St. Paul, is successful.

Betting for the 2012 presidential election is also open at several bookmakers, with odds on offer for three candidates at Ladbrokes, headed by the two most prominent females in U.S. politics. Hillary Clinton is 10/1 to take over her husband Bill's old job in four years time, while current Republican VP candidate Sarah Palin is 16/1. Current Democratic VP candidate Joe Biden is 33/1 to assume the presidency in 2012.