The corporation published point by point responses to The Sun's articles, which ran on Tuesday and Wednesday. The first hitting out at the "staggering pay deals" of BBC executives - a favourite topic in tabloid coverage of the broadcaster - and the second claiming output was tainted by "left-wing prejudices of (a) Guardian-reading elite".
Titled 'The Facts Behind The Sun's Editorials', the BBC response said the cost of its senior managers had fallen dramatically and it recruited from "a wide variety of backgrounds, including newspapers from across the political spectrum".
The BBC press office tweeted the rebuttals by saying The Sun had "shown a lot of interest in the BBC recently - here's what we think".
It was rumoured The Sun's attacks were revenge for the BBC's Panorama expose of Mahzer Mahmood, The Fake Sheikh, which was broadcast last month despite legal attempts to stop it.
Amol Rajan, Editor of The Independent, claimed a "very senior BBC figure" told him this.
News UK, The Sun's parent company, had not responded to requests for comment on this claim as this story went live.
Media insiders on Twitter acknowledged how unusual the BBC's response to of The Sun was and praised it.
Rather enjoying the BBC's newly robust approach to PR (vs The Sun) http://t.co/JujhG5lwQU— ian leslie (@mrianleslie) December 4, 2014
As well as the editorials, The Sun ran a story (£) attacking the use BBC-branded laptops during The Daily Politics Show's Autumn Statement coverage, saying this has triggered "fury".
The show's editor Robbie Gibb protested, saying the branded laptops were "pieces of printed paper stuck on the lid, as the press office explained to you".
@Sun_Politics the "branded laptops" are pieces of printed paper stuck on the lid, as the press office explained to you.— Robbie Gibb (@RobbieGibb) December 4, 2014
Yesterday, the BBC made a rare acerbic comment about a front page in its paper roundup, on the day The Sun called Russell Brand a "hypocrite" because of his landlord's tax affairs.
The BBC said: "It is not clear how these facts might make Mr Brand guilty of hypocrisy."