Horne and Corden played on-screen best friends Gavin and Smithy for the show’s original three-year run, but there was speculation the pair had fallen out after their other joint ventures, including Lesbian Vampire Killers, were panned by critics.
When asked by a Mail Online journalist whether the feud rumours were something he felt the need to address, Horne’s response was indignant: “Well you made it up, so no.”
Horne will reprise his role as Gavin in the Christmas special alongside Corden, Joanna Page, Ruth Jones, Rob Brydon, Larry Lamb and Alison Steadman.
The BBC recently revealed the show would be among its festive TV highlights, alongside Doctor Who, A Christmas Carol and Dracula.
It will air at 8.30pm on Christmas Day on BBC1.