"They've been working together lately," a friend told The Sun. "The attraction and the chemistry between them is clear."
"I know Mel wants to help Matt do well," added the source. "She really thinks a lot of him."
Matt and Mel, who are seen kissing in the video for their latest song Loving You, have appeared to be very close as they promote the new single, although things have not been smooth for the pair.
Matt's liking for nights out and partying has proved difficult for mum-of-one Mel and they are said to be taking things slowly before committing to anything serious.
The duo were spotted walking hand-in-hand in Poland last month and have stepped out together for appearances at BBC and G-A-Y.
Two weeks ago X Factor winner Matt was seen with his arm around the former Spice Girl as they celebrated the addition of Beverley Knight and Tristan Gemmill to the West End cast of The Bodyguard.
Mel, 39, split from property developer Thomas Starr last year. The pair, who were together for ten years, have a three-year-old daughter named Scarlet.