WATCH: Former head of civil service accuses Brexiteers of 'selling snake oil'
The former head of the civil service has launched a full-blooded attack on Tory eurosceptics, accusing them of "selling snake oil".
Gus O'Donnell, who served as cabinet secretary under Tony Blair, Gordon Brown and David Cameron, said attacks on Whitehall officials were "completely crazy" and "ridiculous".
His comments came after Brexit minister Steve Baker this week rubbished government forecasts, and prominent Brexiteer Jacob Rees-Mogg accused the Treasury of "fiddling the figures" to overstate the economic impact of leaving the EU.
Appearing on ITV1's Peston on Sunday, Lord O'Donnell dismissed their claims, saying: "The truth is civil servants operate by the civil service code...their job is to look at the evidence and present it as best they can and analyse the uncertainties, because it's hard to forecast anything and, of course, you won't get it right all the time.
"But that's what they do, they're objective and impartial and I think what you find is that tends to get accepted very nicely when it agrees with someone's prior beliefs but when someone doesn't like the answer, quite often they decide to shoot the messenger.
He suggested that eurosceptics were deliberately attacking civil servants to distract from the weakness of their own case for Brexit.
"We look at the evidence and we go where it is. Now, of course, if you're selling snake oil you don't like the idea of experts and testing your product. And I think that's what we've got, this backlash against evidence and experts is because they know where the experts will go."
And he hit out at the suggestion that Downing Street's chief Brexit advisor, Olly Robbins, was not committed to leaving the EU.
Lord O'Donnell claimed instead that dithering from Theresa May had put Mr Robbins in a difficult position.
"This is completely ridiculous. What Olly wants is a clear steer, some leadership from the Prime Minister and the Cabinet to say 'here's what we want you to argue for, here's what we want'.
"They're taking a little bit of time, these are complex issues, but they must soon come to a decision and I think that's what I would urge.
"If they don't, it'll be like you and I negotiating and you're very clear what you want, and I haven't got a clue - I mean, you're gonna win!"