The XL album currently has a lead of 5,453 units to head the artist albums market at this stage of the week, according to the Official Charts Company, with Elektra/Atlantic act Bruno Mars' Doo-Wops & Hooligans in second place.
It has previously spent 18 non-consecutive weeks at number one, equalling the uninterrupted run of the original soundtrack to Saturday Night Fever between May and September 1978, but will go one better if it climbs back to the top this weekend. This would make it the UK's lengthiest album chart-topper since Simon & Garfunkel's Bridge Over Troubled Water accumulated 33 weeks at number one during eight runs between 1970 and 1971.
The Adele album's sales are 30.9% up on the week up to the end of trading on Tuesday with demand having increased following BBC One screening her Royal Albert Hall concert on New Year's Day. It was at number six on last Sunday's chart, having been named as the UK's biggest-selling album of 2011.
First album 19 is also on the rise again, up 141% on the week and is currently the week's 16th biggest artist album, having been at number 40 on last week's countdown.
There continues to be a close battle to top the singles chart this Sunday with the Atlantic-issued Good Feeling by Flo Rida around 4,000 units ahead of Parlophone act Coldplay's Paradise, which climbed to number one last Sunday. Epic act Olly Murs is a further few thousand sales behind in third position with Dance With Me Tonight.
The full midweek singles and albums charts are on musicweek.com.