Q: How do you know when politicians are lying? A: Their lips are moving. Sure, it’s a very old joke, but it captures how many see present-day politics and professional politicians.

It’s something of a cliché to say we live in the post-truth age but, has there ever been a truth age? From the beginning of time lies have oiled the wheels of human interaction. Most are of the “little white” variety and mostly harmless. We shouldn’t trust anyone who claims never to have told a lie.

Some lies however, are far from innocuous. In Mein Kampf for example, Hitler was well aware of the potential impact of the “Big Lie”. His “fundamental principle was to confine it (the lie) to a few points and repeat them over and over”.

Present day social media operates on much the same principle. Platforms such as Twitter make it easy to spread half-baked messages and theories that are swallowed whole by the gullible. Despite regulation, the advertising industry is only a passing acquaintance of the truth. Paid “influencers” and fake reviews are all part of the marketing strategy to part the unsuspecting from their money. Advertisers sell the “cool” lifestyles of beautiful people that are total fabrications. Some of the world’s biggest companies are less than frank about their products.

Most of us are not totally naïve and we expect retailers and advertisers to sail as close to the wind as possible without actually breaching the Advertising Agency code. We know they’re out to get our money and instinctively apply the principle of caveat emptor.

Things should be different when it comes to politics. Politicians at all levels claim they enter politics to make a difference and improve the lives of the people they represent. As a result, we have a right to expect high standards of honesty and transparency. Far too often however, our perfectly reasonable expectations are dashed. By revising the Ministerial Code, the Prime Minister has signalled that the electorate is being unreasonable by expecting him and his ministers to be honest, act with integrity, to be transparent and accountable. Their sense of entitlement and exceptionalism is truly astonishing.

Mr Johnson has created a cabinet in his own image. They find it easier to lie and dissemble than address the current mess that is largely of their making. Distortion and the downright lie are the go-to responses in every new crisis. Lying has become the factory setting for political life. There is no Brexit dividend; there is no additional £350 million each week for the NHS; the economy is not booming; inflation, borrowing and debt are approaching unprecedented levels. As George Orwell observed, “political language is designed to make lies sound truthful and murder respectable”.

Mr Johnson has taken it to a whole new level. Record producer David Geffen was spot on when stating, “Everyone in politics lies, but to do it with such ease, it’s troubling”. The lies come so thick and fast, it’s like whack a mole. It’s ironic that attempting to refute a lie, such as Keir Starmer’s alleged failure to prosecute Jimmy Savile, simply wins it more air time.

Yet, I have a sneaking admiration for Mr Johnson’s mental resilience. If accused of lying at every turn, most people’s self-image and self-respect would be destroyed. Yet, Mr Johnson floats above it in a state of permanent denial. When making speeches at Westminster and elsewhere, he looks as if he’s having an out of body experience.

We have only have ourselves to blame. We have let Mr Johnson and his like get away with it for far too long. Too few of us take an active interest in politics or summon up the energy to become personally and directly involved. For many, even casting our vote is way too much effort. We have become desensitised and inured to the lamentable state of politics at Westminster and Holyrood. It takes effort to contact our local MPs and MSPs and tell them what we think. Our representatives hold regular surgeries but we don’t get off our backsides, go along and hold them accountable for their voting records and their party’s actions.

A little preparation always comes in handy. The internet makes it easy to fact check most political claims and identify downright falsehoods. For example, how many of the 40 new hospitals promised by Mr Johnson in 2019, have been built?

You never know, some of our MPs and MSPs might even welcome the feedback. Parliamentary democracy at Westminster and Holyrood is being debased in front of our very eyes. If it’s to survive, we can’t go on leaving it to others to hold our representatives accountable. Above all, we need to make it clear that the only way in which politicians will regain the trust and respect of the electorate, is to accept we are sufficiently grown up to deal with the unvarnished and unspun truth.

Our columns are a platform for writers to express their opinions. They do not necessarily represent the views of The Herald.