The Official U.K. Charts Company has refused to add the album to its chart, saying it cannot be proven newspaper sales are “genuine consumer purchases” and could not audit sales accurately.

According to MediaGuardian.co.uk, which has seen a copy of a letter the Mail on Sunday managing director Stephen Miron sent to the charts company this week, Miron demanded the company include Planet Earth on its album chart.

“Given our belief that this album should still be included on the official UK album charts and having responded to your issues, I would urge you to reconsider your previous position as a matter of urgency, before we engage our lawyers for legal advice to force a challenge to this restraint on our trade,” Miron wrote.

After first challenging the promotion, the music chain HMV will sell the newspaper. In addition to the license fee, Prince will also receive royalties from each copy of the newspaper sold.