Harry Styles faces an "incredibly tight race" to land his first solo No. 1.
The 23-year-old singer recently launched his debut track as a solo artist, 'Sign Of The Times', but it's still far from certain he will secure the coveted No. 1 slot later this week, with Ed Sheeran's hit single 'Shape Of You' providing stiff competition.
A source said: "'Sign Of The Times' is only at No. 12 on Spotify overall. That might not be enough when the streaming ratio is properly added come the end of the week."
Harry currently leads Ed by around 10,000 sales, according to the latest figures, but that gap could conceivably be closed by the time the final result is announced later this week.
The insider explained to The Sun newspaper: "'Shape Of You' is still getting 488,000 daily streams to Harry's 277,000.
"It is now an incredibly tight race. It'll be fascinating to see who comes out on top on Friday."
Earlier this month, Harry compared releasing his new music to giving birth.
The One Direction heartthrob admitted that branching out on his own away from the band has left him feeling "vulnerable".
He recently explained: "It's very much like giving birth - without the pain, obviously. It was very exciting. It was nerve wracking. Also, very exciting to have a job again.
"But I think honestly, any time you are putting something out that's kind of a piece of you, I guess it's quite a vulnerable feeling. But it is exciting. I like it. And I think that helps in terms of the nerves. I think if I was putting something out that I didn't like, then I'd be much more nervous."