Nicola Sturgeon: David Cameron 'living on borrowed time'. But, what does she mean?

Is she asking for someone to SAVE the NATION, by making CamMORON into "Spencer Perceval II".?
In #Scotland this is how we roll...Ooh Nicola Sturgeon ooh Nicola Sturgeon ooh Nicola Sturgeon ooh Nicola Sturgeon.
"Why it's not I but Nicola Sturgeon who is out of touch with the common people!" screams David Mundell to an empty…
We said no. It's time the SNP listened.Nicola Sturgeon must rule out #indyref2
Nicola Sturgeon has been leader for years and spends more time abroad than doing the day job in #Govanhill
"A virtual caretaker leader living on borrowed time" - and here's why

"I will smite David even to the wall with it," but David was quick enough to avoid it, and when at another time Saul attempted the same thing, David again slipped aside, and the spear simply struck the wall. This agility of David's made Saul even more angry than before, and increased his fear of the wonderful youth, whom Saul felt had the blessing of God, which had been taken from him. So strong was Saul's dislike of David now, that finally he sent him away from the house, giving him a position where he would have less influence than formerly, for he would be only captain over a thousand men, but the new position only increased David's popularity. He ruled those under him with such wisdom that all the people loved him, and Saul was, of course, more jealous and angry than before, and yet afraid of him too, and he began to think of another way to rid himself of the troublesome rival.
Besides these men, all the others of his little band were devoted to him, seeing his courage and his unconditional dependence on God under all circumstances. The wild, rough life brought out all the manhood there was in his little band of outlaw warriors who were occupied mainly in guerilla warfare with marauding tribes and in eluding the pursuit of Saul, and in this way several years passed, during which time, David's life was full of stirring events, but many a night as he wandered underneath the stars, his thoughts turned in passionate longing to Jonathan, for whom his heart cried out--for Jonathan, whose life was as different from David's, for he had all the comforts of luxurious living, and all the elegance and pomp which were the natural surroundings of a King's son. And yet he was far from happy, for he too longed for David, and he was obliged to spend a large part of his time in watching over his father, whose weakness of character he understood perfectly, and to keep the King from dangerous acts and damaging outbursts of temper, required all of young Jonathan's tact, and most of his time and strength.