According to The Mirror, Dennis volunteered his services when he heard The Wombats' plea for a Liverpudlian celebrity to contribute the spoken-word introduction.
Speaking from the London set of the single's promo video, Dennis said: "They were great and cool and I loved their music... They are a great Liverpool band. I was thrilled to be involved. I think it's great that they have done this."
Dennis plays The Wombats' father in the video for the track, which will go up against the winner of this year's X Factor for the coveted Christmas number one spot.
The Wombats had also expressed an interest in recruiting chatshow host Paul O'Grady for the single, which is released for download on December 15.