Where is the next political scandal coming from? It is not hard to see that Carrie Symonds’s presence inside Downing Street – reportedly decorating her flat with someone else’s money, with a nexus of her friends appointed to key jobs, and her own activist agenda to pursue – is going to brew up a storm. Indeed, it already has.

Carrie has made matters worse by mobilising her mates to wage a Twitter and op-ed war alleging sexism and misogyny against any breath of criticism of her role as an unelected and unappointed adviser to her prime minister partner. As a PR professional herself she should surely have realised that silence is often the best policy.

The history of scandals is littered with examples of affairs that would never have attracted attention or even seen the light of day if only the participants had stayed schtum and not reacted to swirling rumours. If you add fuel to a fire it will burn more brightly. If you ignore and starve it, it will just go out.

Take the current and growing brouhaha surrounding the poisonous feud between the parents of Scottish nationalism: Nicola Sturgeon and her predecessor Alex Salmond. Whatever the final outcome of this convoluted affair, it has already seriously damaged the SNP’s reputation, could end the stellar career of Ms Sturgeon, and may even derail the steady march towards Scottish independence that had hitherto seemed inevitable.

Yet, before he was cleared by a jury, when allegations about Salmond’s behaviour towards women first emerged in public, he was already a busted flush. He had resigned as first minister the day after defeat in the 2014 independence referendum and had lost his seat at Westminster. Why, then, did Sturgeon and her minions not simply sit back and let sleeping dogs not merely lie, but die?

Instead, if Salmond and a growing body of evidence are to be believed, the SNP leadership engaged in a covert campaign to destroy the reputation of the already fatally damaged leader of their party. It was as if the leaders were happily dancing a Highland Reel on a political corpse. Madness.

The same process destroyed lives and careers in two other major political scandals in postwar Britain. If only Liberal leader Jeremy Thorpe had ignored his former lover Norman Scott he could – who knows? – have continued his glittering political trajectory. He preferred to encourage a ludicrous plot to kill the man, succeeded only in murdering his dog, and ended up on trial at the Old Bailey. He was cleared; but his career was over.

Most political events, if safely ignored, are swiftly forgotten by a public with the attention span of mayflies

In the previous decade, Tory war minister Jack Profumo made the fatal mistake of suing two Italian magazines that alleged that he had enjoyed a brief affair with a “model” named Christine Keeler. He then compounded the error by denying the affair in the House of Commons, and, when this was proved a lie, resigned to spend the rest of his life atoning for his mistake in honourably doing social service in London’s East End. If he had only stayed silent until the rumour mills had abated, he could well have become PM.

Across the pond, Richard Nixon would have ended his presidency an elder statesman revered for his role in building bridges with China and ending the Vietnam War had he not attempted to cover up his associates’ breaking into the Democratic Party HQ at Watergate. The break-in itself was as unnecessary as the SNP’s political post-mortem evisceration of Alex Salmond, since Nixon carried every single state except Massachusetts in the presidential election. It was the cover up and tangled web of lies he wove around Watergate that brought Nixon down rather than the original offence.

So far, Boris Johnson wisely seems to be following the example of one of his predecessors in Downing Street in doing little and saying less. H.H. Asquith managed to remain in office for a decade by his policy of prevarication and procrastination; summed up in his favourite phrase, “Wait and see.” If he is ever cornered and questioned about his fiancée’s growing influence, Boris is likely to adopt his usual tactics: retreat behind a barricade of bluster and dismiss it all (as he said in another context) as – “a pyramid of piffle”.

Another previous prime minister, Harold Wilson famously observed that, “A week is a long time in politics,” and it is certainly true that most political events, if safely ignored, are swiftly forgotten by a public with the attention span of mayflies and the memory capacity of goldfish. If the boil of a growing scandal can be swiftly lanced and drained all should be well. If it is covered and denied, its toxins often prove fatal.