WHEN Whitehall mandarins conduct an inquiry there are usually few clues and no fingerprints; the leak remains a mystery and Colonel Mustard gets away scotfree.

 

So it came with a deal of astonishment that this time round, the person responsible was revealed as, at the time, none other than the Secretary of State for Scotland - in the Scotland Office with the offending memo.

It should be remembered that the document's contents were dropped into the middle of the election campaign just when Nicola Sturgeon was riding high following that first UK leaders' debate when the public, south of the Border, got their first real look at the combative and triumphant First Minister.

The leak was designed to do the SNP leader maximum damage. Having told voters that she wanted to "lock out" David Cameron from No 10 and help put Ed Miliband into No 10, the memo alleged that she was in fact a hypocrite because, in private, she was saying the complete opposite.

Despite the frantic denials from both Ms Sturgeon and the French Consul-General, damage was done; not so much to the SNP leader but to the Labour leader.

Mr Cameron within 24 hours was declaring that the FM was revealing in private what everyone knew in public: his rival was not up to the job as Prime Minister.

Now that Whitehall mandarin Sir Jeremy Heywood has reported and lifted the stone to reveal the sorry mess beneath, the real damage done is to Mr Carmichael.

At the time of the leak, he sought to leave the impression that he only knew about the memo's contents after he had been contacted by a Telegraph journalist when, in fact, it was he who had sanctioned the leak by his Spad in the first place.

While Ms Sturgeon sought to leave the next move up to the conscience of the ex-Scottish Secretary, her colleague Stewart Hosie had no compunction in calling for him to resign.

Interestingly at the time of the leak Nick Clegg denounced the PM for "trying to be a sort of one-man detective" by seeking to lay the blame for the leak on the Lib Dems.

"Let's have the inquiry and then, if the person who was responsible has been found, that person should be held to account," insisted the former Deputy Prime Minister.

Of course, his colleague from Orkney could now seek to tough it out but the court of public opinion might well think otherwise.