Volodymyr Zelensky was deliberately blunt, even brutal, when he warned on Friday that Europe could face an influx of up to 20 million refugees if they did not find the money to help cover the costs of Ukraine’s defence.

The Ukrainian president’s growing frustration has driven him to increasingly harsh rhetoric – and now what sounded to many like an implicit threat. Certainly, conservative figures in both Poland and Germany – countries that have taken in many Ukrainians since the war began more than four years ago – have taken it as such.

Europe’s collective memory doesn’t have to go back far to see worrying parallels. In 2016 and 2020, Turkish President Recep Tayyip Erdogan used the threat of opening his country’s borders, allowing millions of Syrian and other refugees to stream into Europe, to extort billions in aid from the EU, along with other political concessions.

Zelensky doesn’t have the human ammunition of over three million foreign refugees camped inside his country, desperate to head across the border, but the Institute of Migration estimates that there are nearly 3.6 million Ukrainians who remain internally displaced within their own country. If conditions worsen this winter, as Russian missiles and drones hammer everything from power lines to petrol stations, more will be tempted to leave the country and head west.

Around six million Ukrainian refugees have already fled the country, including around 230,000 living in the UK. One International Organisation for Migration analyst told The i Paper that “people tend to go where they have heard they will be welcomed, and where there are already larger Ukrainians communities”. Further influxes of Ukrainian refugees are likely to head to Germany, Poland, Czechia and the UK.

When the war does eventually end, Ukraine has been promised quick and generous reconstruction assistance by both the EU and UK. But the country would face many other challenges, especially if a lopsided peace deal had been forced upon it.

There would probably be an outflow of fighting-age men – currently banned by the Ukrainian government from leaving the country – to be reunited with families who have settled abroad after being granted temporary sanctuary within the EU and UK.

Some European countries are already trying to deter more arrivals. More broadly, Italy, Denmark and Poland have been pushing the EU for a tougher collective migration policy. A wave of migration from Ukraine could galvanise populist voices.

Reform UK said last week that it would ⁠scrap all legal routes for asylum resettlement, but keep a temporary settlement scheme for Ukrainians fleeing the war against Russia. It is not clear what would happen if the need became longer term.

Ukraine finds itself in a precarious position, and its president’s stark rhetoric is a clear sign of that. The move could easily backfire, at a time when Ukraine is seeing support from the US ebb away.

Raising the spectre of an influx of refugees is a gamble for Ukraine, which is heavily dependent on continued European financial and military assistance. But Zelensky feels forced to turn to the worst-case scenarios to try to extract greater aid. Hence the spectre of Ukrainians being “pushed out” of their country if Russia is allowed to roll across it.

The prospect of such a decisive victory for Moscow is small. As things stand, defeat for Kyiv looks more likely to involve its military being forced out of its final positions in the Donbas region and having to accept enforced neutrality. After four years of fighting, that would be seen as a painful defeat for many.

While it is maintaining its own campaign of deep strikes against Russian targets, including the largest attack yet on St Petersburg this weekend, Ukraine’s position is difficult. Vladimir Putin seems to believe that Russia can weather whatever damage Kyiv can inflict on it and is not slackening his attacks.

As one diplomat based in Kyiv told The i Paper: “Zelensky sounds angry and desperate, because he is.” He has already accused Donald Trump of betraying Ukraine and, in the diplomat’s words, “he feels the Europeans aren’t doing enough to fill the gap”.

Behind its supportive talking points, the EU is reluctant to keep digging into its pockets. The existing €90bn (£75bn) staged loan Europe has given to Kyiv is proving not to be enough, and according to projections from the International Monetary Fund, Ukraine’s budget deficit could top €30bn (£25bn) in 2027.

The money set aside to cover the fighting in the second half of this year was spent in the first half. As for hopes that Ukraine would be offered a fast-track to membership of the EU, these are also dwindling.

While there’s relief in Kyiv that Andy Burnham’s disinterest in foreign policy means that he is essentially sticking to the lines set out by his predecessors, there is a sense of diminishing returns: that each of Zelensky’s trips to a European capital, while typically rewarded with some new promise of sanctions or assistance, is proving less productive.

The kind of mass exodus of refugees Zelensky has threatened, representing over half of the country’s population, is implausible. Many of the Ukrainian refugees already abroad at least claim that they want to return home once the fighting stops.

But Europe would face consequences, and Zelensky is trying to remind leaders and populations there of the very real threat on their doorsteps. One of those is a Russian victory and the kind of population movement not seen since the Second World War.

Tugging at European heartstrings is no longer working the way it used to. Invoking a shared Russian threat has diminishing impact now that Europe is rearming. Zelensky is having to up the ante, in the hope of scaring and browbeating his allies into offering him more.