A feature film inspired by one of the most beloved British comedy series of all time is airing on TV today, after which it will be available to stream for free for a limited time.

This lesser-known World War II feature is a must-watch for fans of the likes of Blackadder and M*A*S*H as it tackles the tumultuous period of world history with wry British humour.

Dad’s Army is best known as the hit sitcom that ran for nine series on BBC1 between 1968 to 1977.

While it’s still widely adored by millions of Brits to this day, even some of the show’s biggest fans may not have seen the feature film version of the show released back in 1971.

Based on some of the series’ classic early episodes, the film partly serves as an origin story for the iconic Home Guard platoon, with Arthur Lowe returning as Captain Mainwaring alongside most of the principal cast.

Although it’s not quite as fondly remembered by Dad’s Army fans, particularly for some changes made to the original series including the recasting of Liz Fraser as Mrs Pike (originally played by Janet Davies), there are still many who hold the film adaptation in high regard.

The film is airing today (Monday, 24th November) on Film4, after which it will be available to stream free of charge on Channel 4.

One rave review from an IMDb user made the bold claim that Dad’s Army is “Probably the best film of a TV show ever”.

They continued: “TV shows from the 1970’s which were turned into films were usually terrible. Dad’s Army is the big exception.

“The formula from the TV show worked just as well on the big screen and with the bigger budget it’s lovely to see people walking around Walmington-on-Sea. The plot is similar to parts of some of the TV episodes, but that doesn’t matter because they’re still as funny.”

Another die-hard fan gave it 10/10 and said: “Often when TV series are transferred to the big screen, they lose their appeal. Not in this case!

“The historical accuracy in costumes, equipment and general art direction, like the TV series, is outstanding. A good example of comedy and farce, with excellent script and comedy actors in the right parts.”

Praise continued on Letterboxd where one user awarded the film five stars. “The movie is a delight from start to finish,” they said.

“The cast of the tv show are all here (except Janet Davis, who was replaced by Liz Frazer for some reason) and so are the laughs.

“It’s a good film for the whole family to sit down and watch together, since there is no bad language, violence or sex, and the humour is warm and gentle. It shows that even if we have our faults, we can still work hard and get the job done.”

And a final review reads: “I absolutely know this off by heart, having been very into the series as a small child, and was quite fascinated by the way this put a lot of early bits of the series into cinematic form.

“I still think it holds up, it’s still daft, and it still makes me laugh, which is about all I could ask for from a comedy film.”

Dad’s Army is available to stream on Channel 4.