Speaking on the television show, Barnett quizzed Sir Geoffrey Clifton-Brown, deputy chair of the public accounts committee, as he praised Boris Johnson's government over its potential plans, particularly in relation to Mr Johnson's recent clampdown on crime.
The debate comes after Mr Johnson pledged to spend £100 million on prisons in England and Wales, with the aim of cutting crime both on the streets and inside prisons.
Questioning the minister, Barnett said:
Well, let's look at evidence, then, because we can talk about that.
Since 2012, judges already have the powers in this country to hand out longer sentences to violent, or sexual offenders.
So why on Earth is this review necessary?
Clifton then responds:
So what we're going to do, is to have an intelligent approach to sentencing. Some crimes, violent crimes, sexual crimes, may get longer sentences. Other crimes may well get shorter sentences.
And what the prime minister is particularly keen on is for some more minor crimes to have proper community sentences to keep people out of prisons all together.
However, Barnett isn't impressed:
But this isn't you, is it? That's what I'm trying to say. The rules have already been in place for judges to do this since 2012. This is just bluster to get headlines and get votes isn't it...
This is a new approach to sentencing... so that some crimes will get longer sentences, and other more minor crimes will be kept out of prison all together...
Barnett wasn't having any of it:
But we don't need a review. The rule is already there since 2012. We've seen on the chart that sentencing is getting longer, and violent crime is still going up.
It doesn't work based on the evidence, does it. Or are you not a government attached to facts?
Of course we're a government attached to facts...
We think that constitutes what's known in the business as a 'burn'...
People on social media were quick to notice her take-down, and it goes without saying that they loved it.