R&B singer Rihanna's hit Umbrella is set to become the longest-running number one single for more than a decade, according to reports.
Rihanna has just announced her first major UK arena tour
Music Week magazine said the track, which features rapper Jay-Z, is likely to top the chart for a tenth week.
The last song to spend more than nine weeks at number one was Wet Wet Wet's Love Is All Around in 1994.
Meanwhile, Britain's Got Talent winner Paul Potts is set to top the album chart with his debut One Chance.
The album, which was released on Monday, is outselling its nearest rival The Enemy by five to one.
HMV spokesman Gennaro Castaldo said: "It's incredible how TV can take a complete unknown artist and catapult him to overnight chart success."
MOST WEEKS AT NUMBER ONE
18 weeks - Frankie Laine, I Believe (1953)
16 weeks - Bryan Adams, (Everything I Do) I Do It For You (1991)
15 weeks - Wet Wet Wet, Love Is All Around (1994)
11 weeks - Slim Whitman, Rose Marie (1955)
10 weeks - David Whitfield, Cara Mia (1954)
10 weeks - Whitney Houston, I Will Always Love You (1992)
Source: Official UK Charts Company
Potts, 36, was a mobile phone salesman before finding fame on the TV talent show.
"It's unbelievable. Four weeks ago I was in the store selling phones," he said.
Last week Rihanna, 19, announced her first major UK arena tour.
If she does make it 10 weeks at number one, she will become only the seventh artist in chart history to reach double figures.
Three of the previous six came in the early 1990s - Wet Wet Wet, Bryan Adams and Whitney Houston - with the other three soon after the charts began in the 1950s.
Barbados-born Rihanna, who recently performed at the Tokyo leg of Live Earth, released her first UK single, Pon De Replay, in 2005.