Pop band Girls Aloud have taken a small lead in the battle of bands created by ITV1's Popstars programme, unofficial sales figures show.

The girl group's single Sound of the Underground is about 8,000 copies ahead of their rivals' single, Sacred Trust.

The two bands were chosen by viewers of the ITV show and released debut singles simultaneously.

Midweek sales figures suggest Girls Aloud have sold in excess of 30,000 copies.

HMV spokesman Gennaro Castaldo said : "First day sales around the country show Girls Aloud have delivered the first blow in the race for the Christmas number one."

Campaigning

The girl group are favourites to come out on top after bookmakers switched their predictions for the coveted Christmas chart prize.

Simon Dornan, spokesman for Virgin Megastores, said: "As predicted the girls have taken an early lead after first day sales and the difference in sales between the two singles is wider than expected.

"The girls have produced an original record which appeals to both boys and girls alike, and not just teenagers either."

The groups will spend the week campaigning for fans' allegiances with a string of public appearances and publicity stunts.

The boy band's song is expected to fall slightly short and take the number two spot.

The top three records in this Sunday's chart could all be products of the Popstars programme.

Transylvanian twins Monica and Gabriela were laughed off the programme when they auditioned for the girl group.

But a track written by their mother, Cheeky Song (Touch My Bum) released under the name of the Cheeky Girls, is number three in the charts and expected to take the number three spot.