Ananova:

Sam is the hot odds-on favourite to win Pop Idol following heavy betting within the last 48 hours.

Ladbrokes make Sam 1/2, in from 4/6, to win the show ahead of closest rival Michelle whose odds have gone out from 11/4 to 4/1.

Chris remains at 9/2 to win the show and Mark is the rank outsider and favourite to go this week at 10/1.

Two weeks ago Simon Cowell said that if he "had a couple of quid," he would put it on Sam to triumph but Ladbrokes say he still hasn't placed a bet.

Ladbrokes spokesman Warren Lush said: " We're sure that Simon Cowell can spare a couple of quid but we still haven't seen the colour of his money.

"As every day passes Cowell's return gets smaller as Sam becomes an even hotter favourite to win.

"We extend an invitation to Simon Cowell to put his money where his mouth is and will ensure that he has more than a couple of quid on. We'll give him £500 and donate the stake and any winnings to his favourite charity."

"The result bookmakers dread is a win for Mark, who was a 50/1 shot early in the competition, while support for early favourite Michelle has dried up."