You cannot hope to bribe or twist,

Thank God! the Whitehall economist,

But given what the man will do,

Unbribed, there's no occasion to.

HUMBERT Wolfe was originally thinking of "the British journalist" when he wrote his famous lines, but as a career civil servant who, like Sir Nicholas Macpherson was honoured for his public service I suspect he would approve of our subversion of his epigram.

Wolfe, Commander of the Order of the Bath, would surely have taken a dim view of the antics last year of Sir Nicholas, Knight Commander of the same Order, as the Treasury Mandarin drove a gold coach and horses through the traditions of impartiality of the Civil Service.

The day last February is etched in the mind. We assembled in the Point Hotel in Edinburgh, an oft-used venue for political gigs because of its spectacular aspect with the Castle as backdrop, and awaited the Chancellor.

When George Osborne arrived he was what my mother would have called "a dug wi' two tails" as he launched into his killer onslaught about rUK refusing, now and for ever, to permit sterling to be shared with an independent Scotland.

It was intended as a knock-out blow and some sections of the strongly pro-Union press present that day treated it as precisely such. A bullish Chancellor made great play of the advice note from his Permanent Secretary which, in "unprecedented" fashion (his word) he proceeded to distribute.

Only the broadcasters got to question the Chancellor, and in fairness they were focusing on the top line, but when the newspaper journalists finally got a brief word, down in a strange, poorly-lit basement, the tone became less confident.

Had Mr Osborne asked for the advice or had it been volunteered? In either case, when? Given the breach of normal Civil Service protocol, who had cleared it? The newspaper journalists would have gone deeper into these issues but the Chancellor - ignoring Vince Cable's warning about Ministers flying in and out to deliver lectures - had to dash for a flight back to London.

It remained in the memory as one of the key moments of the long-campaign which never quite got the scrutiny or answers that it deserved.

The Macpherson memo was genuinely shocking. In it a civil servant passed judgment on politicians. That's not meant to happen. In a fight between different groups of politicians the civil servant took sides. That's really not meant to happen at all.

Up until last February all the questions about Civil Service impartiality had been one-way. Sir Peter Housden had been traduced on a regular basis by newspapers such as the Telegraph and Mail for supposedly "going native" - a phrase which should give anyone pause for thought.

But what the Civil Service in Scotland did was serve the Government of the day in Edinburgh and that was exemplified by the publication of the White Paper on independence. To many, this was an affront, but it was precisely in line with the rules.

Similarly, Treasury civil servants involved in the tidal wave of material criticising Scottish independence and arguments about the economy, were within the rules. They were producing publications demanded by their political masters of the day.

Sir Peter Housden may have been from Shropshire and attended university in Sheffield, but he did his job and was traduced for it, with snide comments about his national affinities.

Sir Nicholas, by way of contrast, actually broke the rules and was dealt a Get Out of Jail Free card by those most critical of his Scots counterpart. The Treasury mandarin, educated at Eton and Oxford University, simply did not think the rules applied to him.

His view expressed in a lecture this week was that in such an "extreme" case as last year's referendum, in which "people are seeking to destroy the fabric of the state" and to "impugn its territorial integrity", the normal rules of Civil Service impartiality did not apply.

During his lecture entitled "The Treasury and the Union" - it dwelt little on the lack of an oil fund - the mandarin said "the strong recurring conclusion" of his teams' studies was that independence would be against the interests of the Scottish people.

Thanks for that, Sir Nicholas. Given the immense benefit of your Eton and Cambridge education, and not withstanding your Jockish name, you were clearly entitled to destroy all the established rules of British public service in order to save us from ourselves. How can we ever pay such a debt of gratitude?