Let's embark on a mental experiment. Let's imagine that Marine Le Pen was on record as declaring that "Judaisation" was a threat to French civilisation.

Let's imagine that she had told her far-right supporters that public manifestations of the Jewish faith on French streets were comparable to the wartime Nazi occupation. This would be regarded in Britain as profoundly sinister.

The urgent and burning question about the Front National today is no longer anti-Semitism. It is anti-Muslim bigotry

Luckily for her, the leader of the French Front National has never attacked “Judaisation”. Le Pen has reserved her venom for Muslims, at one stage comparing Muslims praying in the streets to the Nazi occupation. She has also warned that what she calls "Islamisation" threatens French civilisation.

And yet despite all this, on Sunday morning at the party's headquarters in Nanterre, Le Pen was handed the platform of a prestigious interview with the BBC’s most respected political journalist.

One innocuous question

Many have criticised Andrew Marr for hosting the Front National leader on his TV show. Others argue that he deserves to be congratulated for pulling off an exclusive interview with someone who stands a chance of becoming the next French president in elections just a few months away.

I can think of no more relevant guest in the week when Donald Trump surged to his unexpected and very frightening victory in the US presidential election.

Marr only asked Le Pen one innocuous question on Islamophobia, gently inquiring whether Muslims were welcome in France

However, I do believe that Marr is open to strong criticism for failing to put the right questions to Le Pen.

Let's not forget that the Front National leader has called for the headscarf to be banned, for the banning of non-pork meals in French schools, and for the surveillance of French mosques.

To be absolutely fair to her, she claims to be speaking up in defence of the French secular tradition as expressed in the national constitution and says she wants the same standards applied to all religions.

However, most observers have little doubt that the targets of her remarks are Muslims, rather than Christians or Jews.

Muslims pray during the Muslim festivities of Eid al-Adha at the mosque in Cherbourg-Octeville, northwestern France in 2015 (AFP) This became obvious when she compared Muslims praying on the streets of French towns to wartime Nazi occupation in a campaign speech to supporters in Lyon in 2010.

"I'm sorry, but for those who really like to talk about World War Two, if we're talking about occupation, we could talk about that [praying the streets], because that is clearly an occupation of the territory,” she is reported to have said.

The evolution of the Front National is part of a wider European pattern. Large sections of the far right have stopped attacking Jews and gone after Muslims instead.

“It is an occupation of sections of the territory, of neighbourhoods in which religious law applies, it is an occupation. There are no tanks, there are no soldiers, but it is an occupation anyhow, and it weighs on people.”

This was a distasteful and ugly analogy, and let's bear in mind that many Muslims are obliged to pray on French streets because there simply aren't enough mosques or prayer rooms.

Yet Marr only asked Le Pen one innocuous question on the subject on Sunday, gently inquiring whether Muslims were welcome in France.

When the response came back, “We are not going to welcome any more people, stop, we are full up,” Marr did not pursue the subject.

Serious double standards

Let’s not forget that Marr is one of the more senior and respected representatives of the British liberal elite.

I am fairly certain that he would have asked further questions had Le Pen given the same reply to a question about any other minority group - homosexuals, blacks, Jews, Hindus.

There is a serious problem of double standards here: Britain has banned a large number of Islamist speakers because their utterances clash with mainstream British values

But Marr let Marine Le Pen’s remark go by without comment, as if she had said something absolutely normal.

This is disturbing.

To be fair, Marr did ask Le Pen about the Front National's historic record of anti-Semitism. However this was an easy question for the French far right presidential candidate to answer.

It has been extremely well-documented that Marine Le Pen has distanced herself from her party's past, and denounced her father’s anti-Semitic views. But the urgent and burning question about the Front National today is no longer anti-Semitism. It is anti-Muslim bigotry.

Anti-Muslim bigotry

It is important to note that the evolution of the Front National in France is part of a wider European pattern. Large sections of the far right have stopped attacking Jews and gone after Muslims instead.

Geert Wilders and his Party for Freedom is an important example of this pan-European phenomenon. In the UK, Nigel Farage’s anti-European Union UK Independence Party (UKIP) is showing nasty signs of becoming another.

Had Marine Le Pen expounded similar views about blacks, homosexuals, Hindus or Jews, Marr would have asked her very probing and probably hostile questions.

Yet it is important to bear in mind that even UKIP regards Marine Le Pen as beyond the bounds of respectability and has refused to have anything to do with her or her party.

I believe there are strong grounds for defining Le Pen as an extremist under the Prevent definition, which states: “Extremism is vocal or active opposition to fundamental British values, including democracy, the rule of law, individual liberty and mutual respect and tolerance of different faiths and beliefs.”

In Britain we have developed a set of practices regarding speakers who classify as extremists. On the whole, they are not permitted to appear on mainstream public platforms. On the rare occasions they do, they are challenged.

In October 2009, protestors stand at the entrance to the BBC headquarters in west London ahead of an appearance of BNP leader Nick Griffin on "Question Time" (AFP) One important precedent concerns the former BNP leader, Nick Griffin. He was allowed on the BBC’s Question Time, but had to put up with a barrage of intense questioning and challenges to his beliefs.

An even more relevant case concerns the heavy grilling Griffin endured from the BBC's Jeremy Paxman over his views on Islam and Asian people on Newsnight. It can be seen here.

These precedents suggest that Marr should have challenged Marine Le Pen far more than he did.

There is a serious problem of double standards here. Britain has banned from this country a large number of Islamist speakers because their utterances clash with mainstream British values.

Yet when Le Pen appeared on Britain's foremost political programme, she wasn't challenged over her views on Islam. I am absolutely certain that had Marine Le Pen expounded similar views about blacks, homosexuals, Hindus or Jews, Marr would have asked her very probing and probably hostile questions.

What British Muslims expect

There are approaching three million Muslims in Britain, almost all of them TV licence payers. The treatment of Marine Le Pen on Sunday would suggest that the BBC deems they have different rights to other categories of the population. I use the term ‘rights’ because I reckon they are entitled to expect that mainstream BBC interviewers asks tough questions when someone who has expressed such strongly anti-Muslim opinions comes into the room.

It is astonishing that one of Britain’s leading newspapers should try and make Islamophobia normal in this way

However, it would be entirely unfair to single out Andrew Marr, who is an excellent interviewer, for this double standard. The entire British public press and broadcast media conducts itself in exactly the same way as Marr and the BBC did on Sunday morning.

Here’s another, even more marked example from The Times newspaper as recently as Monday.

One of its columnists, Melanie Phillips, has excused the bigotry found at the news website Breitbart in the following terms: "Breitbart exposes Islamist violence and intimidation. For that it is called racist, hate-fuelled and Islamophobic."

It is astonishing that one of Britain’s leading newspapers should try and make Islamophobia normal in this way.

This is a problem. I think we all need to reassess the way we engage with right-wing extremists like Marine Le Pen (and for that matter Donald Trump, who has made a series of statements about Muslims in America, which would beyond question classify him as an extremist were he to try and enter Britain.)

This reassessment is urgent. We may be entering another dark age in European history, and Muslims are being held out in particular for unfair treatment, as Le Pen in France and Geert Wilders in Holland show all too clearly.

In the meantime, we need a set of rules that everyone can accept, that are completely fair and transparent, and do not target some communities at the expense of others.

- Peter Oborne was named freelancer of the year 2016 by the Online Media Awards for an article he wrote for Middle East Eye. He was British Press Awards Columnist of the Year 2013. He resigned as chief political columnist of the Daily Telegraph in 2015.

The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Middle East Eye.

Photo: President of French far-right party Front national (FN) and then candidate for the 2012 French presidential election, Marine Le Pen answers journalists' questions as she visits the Mont-Saint-Michel during a visit focused on France's heritage on 23 March 2012 (AFP)