Watch your back, Regis Philbin! The National Enquirer has learned of a new sinister plot to get rid of you at Live With Regis & Kelly… and a spy has been placed on your show to build a case to give you the boot!

According to our top sources, a damning dossier is being drawn up so that TV bosses can carry out their plans to dump the popular 73-year-old daytime TV host.

And, in this devastating development, Regis could be toast by the end of the year — with Dancing With The Stars front man Tom Bergeron as favorite to take his chair.

“Buena Vista Television has put a mole on the staff of the morning show to document every single mistake Regis makes,” said an executive close to the syndicated program.

“And this spy reports back to the corporate offices in L.A., sending them any documentation to support what they believe is wrong with Regis — namely, that he is getting too old! This person has been sending emails back detailing every time Regis forgets someone’s name or makes a flub.

“The suits at [parent company] Disney have convinced themselves that Regis is ruining the show and they want to replace him with someone younger and more ‘audience- friendly’ — in other words, someone who appeals to the 18-49 demographic that advertisers like to sell to so much.

“For a while, it looked as if Survivor host Jeff Probst was a shoo-in take over for Reege. However, recently, the front-runner to replace Regis has been Tom Bergeron, who co-hosted Dancing With The Stars. “Tom is in his early 50s. Execs believe he will be able to appeal to both the younger and older crowd. “They don’t want to be accused of ‘ageism’ — simply getting rid of Regis because he is too old — because that could backfire badly on them and cause a viewer backlash.

“So they decided to quietly build the secret ‘dossier.’ The idea is to gather as much ammunition as possible to make an iron-clad case to can him.

A spokeswoman for Buena Vista Television denied that a spy was cataloging Regis’ bloopers so they could fire him, saying: “We adore Regis.”

For more on Regis, pick up this week’s issue of The national Enquirer, on newsstands now.