Britain's sprinters launch their relay challenge in Paris on Saturday with their medal hopes boosted.

That is because the Americans, winner of five of the previous eight finals, look unusually vulnerable.

Jon Drummond, whose temper-tantrums after being disqualified from the 100m quarter-finals has created a new phrase 'Doing A Drummond' has withdrawn from the championships and world record holder Tim Montgomery has gone home.

Former world record holder Maurice Greene is apparently injured and though America do have strength in depth it could give Britain's quartet a chance.

That is if they manage to get the baton round which they miserably failed to do in the early rounds at the last Worlds in 2001 and the Sydney Olympics missing out on probable medals each time.

Britain will be hoping Dwain Chambers will have shrugged off his 100m disappointments to spearhead them to a likely much-needed medal on the final day on Sunday.