Scottish Labour MP Ian Davidson called it “News-Nat” throughout an interview with presenter Isabel Fraser on Tuesday night.
And former Glasgow Lord Provost Michael Kelly, a Labour activist, added fuel to the fire with a provocative article in The Scotsman yesterday as reported by The Drum.
BBC launched its defence in a letter published in The Scotsman today from Ian Small, its head of public policy and corporate affairs.
Small declared: “Michael Kelly is entitled to his opinions about BBC journalists, however ill-informed and unfair those opinions may be, but we completely ¬reject suggestions of bias on the part of our journalists working on Newsnight Scotland or, indeed, on any other of our programmes.
“When Mr Kelly says Isabel Fraser ‘has form’ it is as one of the BBC’s most highly respected and valued journalists.
“Ms Fraser did what BBC journalists do week in, week out when she robustly, but fairly, challenged the views of Ian Davidson MP on Tuesday evening’s show.
“It may be uncomfortable for some when we ask the questions that our audiences want asked – but that is what we will continue to do and will do so as professionally as Isabel Fraser did on Tuesday.
“To suggest that by asking these questions she holds or promotes a particular opinion is, quite fundamentally, to misunderstand political interviewing.
“Audiences expect fair and impartial journalism from the BBC and they expect those who hold power to have their arguments robustly challenged.
“That is what we will continue to do on their behalf.”
However, in another new development to the story today, The Herald’s political editor, Magnus Gardham, claims the row escalated ...”after it emerged an apparently neutral constitutional lawyer interviewed by the programme was an SNP blogger”.
Gardham reports that Davidson, who refused Fraser’s on-air demand for a public apology, has stepped up his attack when it emerged an expert who contradicted him over the legality of Alex Salmond's referendum plans was a self-proclaimed SNP supporter.
Gardham explains: “However, Andrew Tickell was introduced simply as an Oxford University lawyer without mention of his role as a high-profile Nationalist blogger, who writes online under the pseudonym ‘Lallands Peat Worrier’.
“During his interview, he rubbished a report from Westminster's Scottish Affairs Committee – chaired by Mr Davidson – which concluded that Holyrood probably does not have the legal powers to hold an independence referendum.
The Herald reports Davidson is now calling for an apology from BBC Scotland, and quotes him as saying: "It's outrageous the BBC should act in this way, presenting an SNP activist and blogger as an impartial academic.
"The issue for me is whether Isabel Fraser knew his background. If not, she was incompetent. If so, this was a conspiracy.
"I was clearly being set up by someone for an ambush. Either way I deserve an apology for the way this programme was conducted."
The Herald quotes a BBC Scotland spokeswoman as saying: "We often have contributors on Newsnight Scotland to talk about their area of expertise and add to the debate.
"In Andrew Tickell's case, this is constitutional law."
The BBC responded to Kelly's comment with a statement issued yesterday to The Drum that read; “We absolutely refute any suggestions of bias as Isabel Fraser clearly pointed out on the programme.”