(400m/4x400m relay)

The 400m has been traditionally a strong event for the British team over the past 15 years.

And in Mark Richardson, Britain has another genuine medal prospect to follow in the footsteps of the likes of Roger Black and Derek Redmond.

Victory in Edmonton, which has to be regarded as a possibility, would be be sweet for Richardson who has been embroiled in a drugs row for much of the last 18 months.

In October 1999, Richardson was the latest in a long line of athletes to test positive for nadrolone. He has always protested his innocence and had the backing of UK Athletics dismissed disciplinary action.

However, the sport's governing body, the IAAF, refused to do likewise and banned the Windsor, Slough ad Eton athlete for two years.

Richardson missed the Sydney Olympics as he prepared to defend himself and his efforts were finally rewarded when he was reinstated under the IAAF's "exceptional circumstances" rule.

The IAAF cited his efforts to educate athletes about the potential dangers of using nutritional supplements which he said were to blame for his positive test.

Richardson has made the most of his second chance since his return to competition in June. He won his first inidividual race back, beating US champion Antonio Pettigrew in Glasgow.

An exceptional final 100m in the Grand Prix meet at Crystal Palace saw him conquer another high-class field and has raised expectations of a World Championship medal.