The National:

ASKING difficult questions of politicians is supposed to be what journalism's all about. So, when an MP has an obvious weakness, pressing them on it reaps rewards.

Now, let's flash back to LibDem leadership candidate Jo Swinson appearing in a debate on the Victoria Derbyshire show. Swinson was asked if she was a hypocrite for supporting a People's Vote on Brexit but not a second Scottish independence referendum.

She replied: “No, because there’s a big difference. As I said, in 2014 in Scotland, we had a debate which was based on a very detailed White Paper – which to the SNP’s credit they put forward – that said this our plan for an independent Scotland.”

But the situation would have changed if Scotland was taken out of the EU against its will, wouldn't it? Derbyshire put that to Swinson, who continued: "There’s not a mandate in Scotland to have a second independence referendum, the SNP have been putting forward their case and they have been losing seats."

This is, of course, nonsense, as our recent fact-check showed.

Between the SNP's victory in the 2016 General Election and 2017 Holyrood election on manifesto promises to hold an independence referendum if circumstances changed – such as being taken out of the EU against our will – and the Scottish Parliament voting in 2017 to request powers to hold a referendum, there is a triple-lock on the mandate for an independence referendum.

Not only is Jo Swinson wrong on one count then – she's wrong on three. And yet in interviews even now, several days after that debate, Swinson is giving that same answer to the question.

In a discussion on Sky News, she went down exactly the same lines.

Like Derbyshire, Adam Boulton put it to the MP that if Scotland was dragged out of the EU, it will have been a change in circumstances.

Swinson said: "The SNP do not have a mandate for this. They do not speak for Scotland. They lost seats at the last election."

Boulton pointed out that the SNP still won that election in Scotland, and again said that, amid Brexit, "shouldn't they have a say?"

At no point did the presenter on this show – or any others – point out the simple fact that the SNP have a mandate. Several.

Why is she not being pulled up on this blatant lie? If the LibDems were elected on a manifesto promise to hold a People's Vote, would an MP claiming they had no mandate go unchallenged? They would surely be ridiculed.

But when the ridiculous claim is about Scotland... it seems to go unchallenged.

Swinson's continued insistence that there is no mandate for an independence referendum flies in the face of reality. She must be questioned on this.