The headline of France's Le Monde declares that "pro-Europeans are in a state of panic" as their "trump card of the economy hasn't convinced voters, especially in the Labour camp".
It says that "away from cosmopolitan London, the public sees Brexit as the best way of stopping the influx of East European workers. Meanwhile, spirits sink in the European Council and Presidency."
For the paper's London correspondent Philippe Bernard, there is no doubt that migration is "at the heart of the campaign".
He says that if the Brexit camp wins, it will be as much because an "obsession with foreigners, hammered in for decades by the tabloid press, seems to have taken hold among British voters".
European Union analyst Vivien Pertusot sets the tone for much European comment when he tells France's Le Figaro that Brexit would mean a "voyage into uncharted waters", given the lack of precedent for a member-state to negotiate its departure from the European Union.
"It's a realm of pure legal speculation, and a paradise for lawyers," he warns.
'Please don't go!'
Germany's Der Spiegel magazine makes its views clear with a bilingual front cover pleading with Britain to stay.
Its editorial is blunter in telling voters they "face a choice of opting for a moment of pride, or working together for a common future. If Britain is wise, it will remain in the European Union - because this is about the future of the West", it says, warning of the impetus Brexit would give to right-wing populists across the continent.
Die Zeit also wants Britain to feel the love, juxtaposing a heart and the Union Flag on the masthead of its online edition.
Its correspondents have roved beyond London, only to find "Europe opposed, from Glasgow to the south". "What is driving the British into the arms of the Eurosceptic UKIP? Sometimes despair and a sense of powerlessness, and the feeling that no-one else will help them," reports Philip Faigle from Sunderland.
Die Welt says the vote is still too close to call, while "Europe looks on in apprehension".
The Dutch Algemeen Dagblad, like Der Spiegel, uses a striking front cover to quote the old song "Don't leave me this way".
"We not only love you, we need you. Who else supports us in keeping common sense on this turbulent continent of ours?" it pleads in English. "An EU without the UK would be like tea without milk. Bitter. So please, stay. Stay with us".
'Unconventional measures'
Italian papers, like Il Giornale, focus on the "parachute" of measures the European Central Bank is planning to cope with a possible British exit.
La Stampa thinks Bank president Marco Draghi could even have "unconventional measures" in mind to stabilise markets.
Il Corriere turns to the estimated 600,000 Italians who live in Britain and make London the "seventh largest Italian city".
It says that while some hope Brexit might mean lower taxes, most worry about the possibility of "visas, quotas, and limits to health care" in the general mood of uncertainty.
Spanish commentators also fear financial turmoil. "Europe is working on an urgent response to the Brexit risk," declares El Pais on its 15 June front page. El Mundo agrees that "fear of the UK leaving the EU is damaging markets".
El Pais columnist Luis Garicano sees Brexit as undesirable for both Britain and Europe, but adds that it could be an "opportunity" for Europe to "create a sound fiscal and monetary union that will operate for the benefit of all citizens".
In Poland, Gazeta Wyborcza says Britain should "not be so naive as to expect much goodwill from the rest of Europe" in the event of Brexit, while Newsweek Polska deplores what it calls a British tabloid "media war in support of Leave".
Hungary's Portfolio financial news site thinks the latest polls mean it is "time to start worrying" about the likelihood of Brexit, and Miklos Bonta tells Nepszava that Britain has "let the genie out of the bottle by comprehensively blackmailing Europe, but now it can't find the stopper".
Czech Radio wonders whether Brexit might lead to Czexit next. "Is Europe ready for the domino effect?" it asks.
But, bucking the trend of gloomy reports, the Czech tabloid Blesk suggests Britain could recover from any short-term blow to growth post-Brexit.
"The long-term impact is not clear and, some estimates say it could even have a positive effect on economic growth," it says.
'Blow to integration'
On the EU borders, commentators are also assessing the likely impact of the referendum.
Russia's Komskomolskaya Pravda sees advantages for the Kremlin in a vote to Leave, saying it would weaken the pound and the euro, and "allow Moscow to work directly with London, without having to look over its shoulder at Brussels".
In Ukraine, financial analyst Vitaly Sharan warns the KP v Ukraine newspaper that a falling pound and euro could "drag small regional currencies down with them".
And Mensur Akgun in the Turkish paper Karar thinks Brexit would "boost those nationalist parties unhappy with deals struck in Brussels. It will be a miracle if European integration, already shaken by the economic and refugee crises, survives a decision to leave".
BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring  on Twitter and Facebook.
With a week left before Britain's EU referendum, papers across Europe focus on opinion polls results suggesting a surge in support for the Leave option.