Jeremy Vine's Channel 5 show did not make it to air on Monday after a "significant" power outage affecting ITN, which makes the programme.
The daily talk show, which usually runs from 09.15 to 12.15 BST, was replaced with re-runs of shows such as Million Pound Home and Police Interceptors.
Vine tweeted half an hour before he was supposed to go live to say the team were all still sitting in reception.
ITV's lunchtime news and Channel 4's 11.30 news, made by ITN, did go out.
Mass power outage at ITN HQ - the building which makes the news for @itvnews, @Channel4News and @5_News - as well as @JeremyVineOn5— Lauren Clarke (@rensyclarke) April 4, 2022
Everyone working in reception. Bear with us today - we're all doing this old school! https://t.co/OVyz6iCfVf
In a statement, ITN said: "A power outage this morning has affected a number of buildings and businesses in the Gray's Inn Road area.
"We have therefore moved to our backup protocols to protect our news output, which has continued to air today."
According to the Press Association, the back-up generator reportedly failed early on Monday at the ITN building in central London.
Vine later wrote: "Sorry to say, we didn't make it to air today. Questions will be asked of the emergency generator, and the emergency backup generator. But nice to get some quality catch-up time with my esteemed co-presenter @StormHuntley."
Staff received an email at 08:30 which said there had been a "significant power outage".