In my decades of journalism, I have constantly railed against the defamation law as a damnable impediment to free speech; to the exposure of political malfeasance; and to democratic principle itself because without a well-informed electorate there can be no democracy.

But the boot is now well and truly on the other foot. Hitherto, politicians like Bob Hawke used to boast of the Fairfax swimming pool or the Packer tennis court in reference to their richly undeserved settlement gains through defamation actions arising through some trifling affront that caused them little or no harm.

But let's look at Dutton's statement about the CSIRO report. He said that the report was discredited, and failed to take into account pertinent matters like the cost of rewiring the grid for renewables.

"It's not relied on," he said. "It's not a genuine piece of work. It doesn't take into account some of the transmission costs, the costs around subsidies for the renewables." He said the report was "skewed".

And the facts? After adding $30 billion in new transmission lines and backup, it said that by 2030 with a grid of 90 per cent renewables, electricity would cost between $70 and $100 per megawatt hour.

Coal power would be $85 to $135 and small nuclear (if it ever gets off the ground) $210 to $350.

Large nuclear is off the planet because Australia would have to start from scratch and cannot be compared with other countries which already have it.

Now freedom-of-speech principles suggest people should be allowed to express their opinions, but those opinions have to be based on the facts truly stated. Dutton's opinion is based on made-up "facts".

Dutton is spouting a demonstrable falsehood that the CSIRO report had not taken into account the full costs of rewiring the grid for renewables. A year 12 student could have seen that that is not the case.

So, his opinion is based on a falsehood and so should not be protected free speech. He should retract it and apologise, or the authors of the report should sue him.

Dutton's stand smacks of Trumpism. With Donald Trump, the conclusion is the axiom: renewables are bad. So all the of premises have to be based on the "conclusion" and any of the premises that are contrary to the conclusion are branded as false. They are lied about.

Dutton's statement may seem a trivial, technical misinterpretation that should be ignored. But no. As the head of the CSIRO Doug Hilton said, "When your integrity is questioned, that can have a big impact on individuals and, if left unchecked, it can have a big impact on the community."

The key words are "if left unchecked". That is why the authors should sue Dutton. My guess (after yonks of advising, teaching, and as a newspaper executive being on the raw end of defamation law) is that they would win.

It is highly defamatory of a scientist to say they were skewing their work; that it was not a genuine piece of work; and that it is not relied on (as in the scientist's peers reject it).

We have had a huge debate about truth in political advertising and in political discourse generally. Well, here is a big chance. The authors should give Dutton a notice of concerns and ask for a retraction and apology. Failing that, make him pay up.

It is now imperative that we do not let falsehoods go unchecked. Unchecked falsehoods are the base for people like Trump and Vladimir Putin and should not go unchecked in Australia.

Being sued would be a salutary lesson for politicians who try to base their "facts" on what they want their conclusions to be. Democracy relies on voters being informed - not being fed garbage based on falsehood.

Here we have the other side of Australia's constitutional defence based on representative democracy demanding some freedom of political expression so the electorate is informed. That defence should exonerate any media for accurately reporting any of the lies and misinformation spouted by elected politicians, but not exonerate the politicians themselves, in the interests of an informed electorate.

Dutton said of his statement, "I think it was a fair point to make."

No, it wasn't. It was unfair, because it was based on a falsehood. It was defamatory, and damaging to the scientists and Dutton should be held to account for it.

Since the rise of the self-publishing, unrestrained internet, truth has gone out the window. The self-publishers do not even attempt to verify even the most outrageous claims. The claims go to the masses without any accountability or consequence. Many of the masses swallow the claims as truth. Which is what Dutton and Trump want.

The masses swallow it because consumers of the written word had (pre-internet) become accustomed to believing what they read based upon the commercial and legal reality that it was always in the publishers' interests to get it right as best they could, as their publishing reputation depended upon it. But with the internet the publishers no longer care.

Alas, the internet is not old enough to have inculcated a new norm: that everything you read should be treated as false until you find a way to verify it or find a way to trust the source.

We simply should not allow politicians to get away with falsehoods and use every weapon available to prevent it, even if the hitherto maligned defamation law Is one of them.

It should worry those politicians who distort the truth for cheap political ends.

The adage was: Dog bites man is not news. Man bites dog is news. Let's rephrase that: politician sues publisher is not news. Publisher sues politician is news. And by "news" I mean the search for, and publishing of, the truth.