Republicans step up campaign on eve of Denver

The Republicans are gearing up for a two-pronged attack on Barack Obama's presidential campaign as the Democratic party begins their convention in Denver today. The camp of Obama's Republican presidential candidate John McCain responded to his selection of running mate, Senator Joe Biden, with two new television "attack" ads.

The commercials target Biden, using footage of him criticising Obama as well as sound-bites of Hillary Clinton saying that "you never hear the specifics" about his plans and that "Senator Obama's campaign has become increasingly negative".

Republicans are trying to win over Clinton supporters, many of whom are still angry that the former First Lady was not considered as a running-mate. On one McCain advertisement, a female voice says: "She won millions of votes, but isn't on his ticket. Why? For speaking the truth."