When the Whistle Blows is the show-within-a-show sitcom created, co-written by and starring Andy Millman. It was first mentioned in episode 1.3, as a script that Millman had written and given to Darren, who neglected to read it (in a recurring joke, he would frequently forget the name of the show, often calling it Where the Wind Blows and even confusing it with The Wind in the Willows). The script was turned into a sitcom on BBC One in the first season finale, after Millman gave the script to Patrick Stewart. Excerpts from the sitcom are featured in the second season, and many of the Extras second season plotlines revolve around Millman's experiences on and around the show.  When the Whistle Blows is set in a Wigan factory canteen. The humour is broad and lowbrow in the manner of many catchphrase-based sitcoms. The main catchphrase of the show, "Are you 'avin' a laugh?," is spoken by Millman. The show is unpopular with critics but popular with the public. It does receive a BAFTA nomination, although Millman suspects it is there simply to make up the numbers, and in the end it loses to an unspecified programme by Stephen Fry.  Millman is deeply unhappy with the show, feeling that too many people have interfered with his original ideas in the hunt for ratings. It appears that Millman originally set out to do a comedy similar to The Office, with true-to-life characters in a realistic work environment, without a studio audience or canned laughter. After being forced to collaborate and compromise many of his ideas with producers at the BBC, the show is transformed into lowest common denominator fare with each character having his/her own catchphrase which are repeated ad nauseam to the delight of its 6 million viewers. The show is further debased by the unexplained guest appearance of Coldplay's Chris Martin, in episode 2.4, which bears no relation to the plot and which Millman openly opposes, going so far as to utter the on-camera line, "Chris Martin, what are you doing in a factory in Wigan? It's mental!"  The presence of studio audiences/canned laughter, and the reliance on funny wigs, costumes and catchphrases for humour is a comment on British comedy hits such as Little Britain and The League of Gentlemen. Many people that Millman sees at the recording of the pilot wear T-shirts displaying comedy catchphrases, such as "Wassup", "It's Chico Time", "I'm a lady!", "Am I bovvered?" and "Garlic bread?." (These shirts are not shown in the US version of Extras.) Some of the reviews that the show gets refer to it as a "time warp comedy", and Millman's character talks about 1970s catchphrases such as Mr Humphreys' "I'm Free" (from Are You Being Served?) and Frank Spencer's "Ooh Betty" (from Some Mothers Do 'Ave 'Em), suggesting that it is also partly sending up 1970s British comedy. In episode 2.5, Germaine Greer suggests that When the Whistle Blows is "sub Carry On".

Answer this question "Who does Millman feel interfered with his original ideas?" by extracting the answer from the text above.
After being forced to collaborate and compromise many of his ideas with producers at the BBC, the show is transformed into lowest common denominator fare