A couple of days ago, I saw TV footage of the outspoken Labour MP Jess Phillips on the campaign trail, seeking re-election in her suburban Birmingham constituency.

She was asked which issues voters mentioned most often on the doorstep. Ms Phillips did not miss a beat.

‘Immigration comes up...’ she said thoughtfully. And then, as if remembering herself, she started talking about bin collections instead.

Journalist Douglas Murray said that our political leaders have knowingly colluded in the ‘mass movement of peoples into Europe’

It was, I thought, an enormously revealing moment. For there is no issue so potentially dangerous as immigration. Many people have intense feelings about it, and many feel unable to raise them publicly.

Even in private, self-consciously tolerant people discuss immigration very tentatively, if at all.

The shadow of Enoch Powell — the Birmingham-born Tory who was cast into the wilderness after his controversial speech in 1968 about ‘rivers of blood’ (a phrase he never actually used) — still hangs over the debate.

A few years ago, I was at a lunch in London, sitting next to the former editor of a national newspaper and the editor of one of Britain’s best-known magazines, both of them highly educated and liberal-minded people. The subject turned to immigration.

‘It’s gone much too far,’ one said. ‘You’re quite right,’ said the other, ‘but of course you can’t say so.’

The journalist Douglas Murray has no such qualms. Best known for his acerbic columns in the Spectator magazine and his prize-winning book on the Bloody Sunday inquiry, he has just hurled a literary hand grenade into the debate about immigration and identity in today’s Europe.

Indeed, the opening lines of his new book, The Strange Death Of Europe, could hardly be more incendiary.

‘Europe is committing suicide,’ Murray writes. ‘Or at least its leaders have decided to commit suicide... As a result, by the end of the lifespans of most people currently alive, Europe will not be Europe and the peoples of Europe will have lost the only place in the world we had to call home.’

In his book The Strange Death Of Europe, Murray (left) writes that leaders are filling ‘cold and rainy northern towns’ with ‘people dressed for the foothills of Pakistan or the sandstorms of Arabia’

The causes, he thinks, are twofold. First, our political leaders have knowingly colluded in the ‘mass movement of peoples into Europe’, filling ‘cold and rainy northern towns’ with ‘people dressed for the foothills of Pakistan or the sandstorms of Arabia’.

Second, he believes Europe’s intellectual and cultural elites, including those in Britain, have ‘lost faith in its beliefs, traditions and legitimacy’. Crippled with guilt, obsessed with atoning for the sins of empire, they have lost sight of the historic Christian values that their people expect them to defend.

As a result of their deluded utopianism, Murray thinks, Europe is ceasing to be Europe. Indeed, he believes that European culture as generations have understood it — the culture of Michelangelo and Mozart, Shakespeare and Goethe, Dickens and Wagner — is doomed.

‘Instead of remaining a home for the European peoples,’ he writes, ‘we have decided to become a “utopia” only in the original Greek sense of the word: to become “no place”.’

You will not be surprised to hear that Murray’s book has gone down badly with the bien-pensant types at The Guardian, whose reviewer described it as ‘gentrified xenophobia’ and a ‘slightly posher’ version of ‘naked racism’.

In its way, that verdict tells you all you need to know about the intellectual blinkers of the liberal intelligentsia.

I opened Murray’s book this week with slight scepticism, and I still think he overdoes the apocalyptic negativity.

Outspoken Labour MP Jess Phillips was speaking on TV when she suddenly changed the subject so as not to talk about immigration - showing the stigma people attach to the subject

Even so, at the risk of being accused of xenophobia by The Guardian — which would admittedly put me in crowded company — I believe he has penetrated closer to the heart of our current discontents than legions of liberal academics.

For one thing, it is refreshing to get some honesty about the historically unprecedented nature of immigration into Europe in the past 70 years.

In case you need reminding, the figures for Britain alone are simply mind-boggling.

Between 1997 and 2010, for example, the last Labour government allowed a staggering 2.2 million people to settle in this country, the equivalent of two Birminghams.

Under David Cameron, the Tories promised to reduce immigration to the tens of thousands. Yet the latest figures show that annual net migration is about 273,000, roughly a city the size of Hull arriving every year.

It is worth noting, by the way, that mass immigration has always been immensely unpopular. When I wrote a history of Britain in the Sixties, I could hardly fail to notice that even back then, at least seven out of ten people were dead against it, as shown by the deluge of approving letters that greeted Enoch Powell’s supposedly toxic speech.

Maybe his admirers were wrong; maybe they weren’t. But whatever your own view of immigration, there has never been an issue on which the political class has so consistently gone against the wishes of the British people.

At this point in the argument, your standard liberal academic would typically interject to insist that Britain has always been a nation of immigrants. We all come from somewhere else anyway, they say, we are all mongrels, so how dare we close the gates to a few more?

But as Douglas Murray shows, this is a shameless rewriting of our past. For most of our history, we have never been a nation of immigrants. Even the most famous influx in our history, the Norman Conquest, involved a tiny population transfer, the equivalent of no more than 5 per cent or so.

He believes Europe’s intellectual and cultural elites, including those in Britain, have ‘lost faith in its beliefs, traditions and legitimacy’ (pictured, the Calais jungle)

As much as the BBC and other news organisations like to pretend that Britain has always been a beacon of diversity, the plain fact is that until the mid-20th century the massive, overwhelming majority of the people who lived here had been born here. Look at photo after photo from late Victorian London and the uniformly pale faces stare back at you.

The arrival of the French Huguenots in the 1680s, often cited by apostles of diversity, involved about 50,000 people, all of whom were white and Christian.

And although the Irish migrants who arrived in the 19th century faced more than their fair share of prejudice, our islands’ interlinked histories meant they were far from complete outsiders.

Liberal-minded types often find this embarrassing. Either they try to rewrite our history, relentlessly playing up the presence of tiny minorities of Africans and Asians, or they peddle a caricature of pre-Fifties Britain as a grey, boring place, which desperately needed an injection of immigrant colour.

This is not just a British hang-up. As Murray writes, European liberals love to paint their own societies as ‘slightly boring or staid places’. They write as if ‘there is a hole at the heart of Europe which needs filling and without which we would otherwise be poorer’.

(By the way, this is something they would never dream of saying about countries such as Bhutan or Burkina Faso. Nobody ever suggests that what these unforgivably monoracial countries need is an influx of migrants from Surrey.)

As a superbly damning example, Murray gives us the views of the impeccably liberal Fredrik Reinfeldt, Sweden’s Prime Minister between 2006 and 2014, who enjoyed the dubious reputation of being the ‘Scandinavian David Cameron’. He was a passionate advocate of mass immigration. Swedish people, he once said, were ‘boring’, while national borders were ‘fictional’ constructs.

And in a perfect illustration of what Murray sees as the European elite’s chronic self-flagellation, Mr Reinfeldt even declared that ‘only barbarism is genuinely Swedish. All further development has been brought from outside’.

This would have come as a shock to the Swedish playwright August Strindberg, the film director Ingmar Bergman and the members of Abba, not to mention their countrymen who invented the seatbelt and the pacemaker.

It is refreshing to get some honesty about the historically unprecedented nature of immigration into Europe in the past 70 years

In any case, the results of Mr Reinfeldt’s liberal utopianism have been staggering. With just 10 million people, Sweden has taken in more refugees per capita than any other country. In 2015 alone, it accepted 180,000 incomers — more than the population of all but the three largest Swedish cities.

In recent months, the relationship between immigration and crime in Sweden has become hugely controversial. This is thanks largely to Donald Trump’s comments about ‘riots’ in Sweden based on a report on Fox News, which blamed an alleged breakdown in law and order in the country on an influx of migrants over the past 20 years.

But as Murray suggests, the really telling story is surely the rise of the far-Right Sweden Democrats — a nationalistic, anti-immigrant party that has come from nowhere to lead the opinion polls for the past two years. And this not in Thirties Germany but in 21st-century Sweden, ostensibly one of the most contented, tolerant and egalitarian societies on Earth!

It would, I think, be unforgivably lazy to blame this on the supposed racism of the great unwashed, as liberal intellectuals love to do.

In fact, almost every indicator shows that old-fashioned, poisonous prejudice has virtually died out, not just here in Britain, but across much of Western Europe.

Whatever The Guardian might think, Murray himself is not racist. Indeed, he writes movingly about the plight of the thousands of refugees who have paid up to $1,500 (£1,150) each to travel on dangerous boats across the Mediterranean. As he remarks, any decent person should want to help them, not to ‘push them back into the sea’.

Between 1997 and 2010, for example, the last Labour government allowed a staggering 2.2 million people to settle in this country, the equivalent of two Birminghams

His own approach, by the way, would be for European countries to invest in holding centres in North Africa and to grant refugees asylum for a limited period only.

Whether this would work is impossible to say. But could it really be worse than the free-for-all of the past few years?

But I suspect his trenchant dismissal of all those naive liberal pieties will strike a chord with people in every corner of our political landscape. He pours scorn, for example, on the argument that immigration has magically made us a more tolerant society.

A survey of attitudes to homosexuality in 2015 found that just 16 per cent of people outside London thought it was morally wrong. The figure in London was 29 per cent, reflecting the much higher concentration of conservative Muslims.

Indeed, that conflict between Islamic fundamentalism and British tolerance is a sadly familiar story, from the death threats to the author Salman Rushdie over his novel The Satanic Verses to the horrific murder of Fusilier Lee Rigby by two Islamist converts.

Murray should have made it clearer, I think, that the vast majority of British Muslims are decent, peaceful, law-abiding citizens. Even so, he is absolutely right to argue that, for far too long, our political and cultural elites have been so afraid of being called racist that they have allowed Islamic extremists to fester unchecked.

Yet even now, the European political elite are desperate to silence their critics. Indeed, two stories from Murray’s book genuinely shocked me.

The first comes from September 2015, when German Chancellor Angela Merkel reportedly asked Facebook’s founder Mark Zuckerberg what he was doing to stop people criticising her open-door migration policy on his site. ‘Are you working on this?’ she asked him — and he said that he was.

Under David Cameron, the Tories promised to reduce immigration to the tens of thousands. Yet the latest figures show that annual net migration is about 273,000, roughly a city the size of Hull arriving every year

My shock was twofold: that she felt entitled to ask him to shut down her critics, and that he meekly said he was doing it.

The second also comes from Germany. A month later, in the small city of Kassel, 800 migrants were due to arrive under Mrs Merkel’s scheme, so the authorities held a public meeting.

But when residents began to voice their concerns, the district president, Walter Lubcke, spoke up. Admitting immigrants, he said, was the German way. Anybody who did not agree, he added, was ‘free to leave Germany’.

This is outrageous, I think, not just because it is so arrogant, but because it is so counter-productive. For the past 50 years, the European political elite have been telling the people that they are wrong.

When the voters refuse to listen, the elite merely take that as proof that they need another dose of diversity to break their resistance once and for all. And so the dialogue of the deaf goes on.

Whether this really marks the end of European civilisation, as Murray claims, is a matter of opinion. I think he is far too pessimistic, although if I lived somewhere like the concrete Parisian suburb of Saint-Denis, a crime-ridden ghetto with a heavily North African Muslim population, I might think differently.

What is certain, though, is that we need caustic, but honest, voices like his if we are ever going to have a genuine debate about all this.

For by shouting down and silencing the Douglas Murrays of this world, the bien-pensant liberals are merely handing yet more ammunition to the strutting demagogues of the extreme Right.

I cannot think of a more foolish and dangerous approach. After all, we have seen that story before. We all know how it ends.