The 23-year-old quit the group in March last year (15) and launched a solo career, and while his debut solo record Mind of Mine is set to chart at number one in the U.K. on Friday (01Apr16), his sales pale in comparison to what his former band achieved.

The album had sold 19,848 copies by Thursday night (31Mar16), according to Britain's The Sun newspaper, and is expected to hit 23,000 by the time the chart is announced, which is in stark contrast to the hundreds of thousands One Direction sold.

Their most recent album Made in the A.M. achieved 93,000 sales in its first week, while 2013's Midnight Memories, the last album Zayn appeared on, sold 237,000.

A source tells the publication the disappointing sales could be down to Zayn's lack of promotion in the U.K., including a cancelled interview on BBC Radio 1 and The Graham Norton Show.

"Zayn might be No1 but the sales will give him and his team a big fright. They have only got themselves to blame... Zayn has focused his attention on the U.S. market - and the album is performing really well over there.

"But he has barely given any time to pushing the record here. He cancelled a lot of planned promo and that ultimately has cost him."

His album shot straight to the top of the U.S. iTunes chart, and his debut single Pillowtalk officially charted at number one in both the U.K. and U.S.

"Zquad (sic) thank you dreams coming true right now," he tweeted earlier this week (beg28Mar16) about the support for his record.