Morten Løkkegaard made the call in an advert sent to UK-dwelling Danes' Facebook and Instagram accounts, as part of a Lib Dem campaign for EU citizen's votes mounted in 23 different languages.
“I'm in a hurry to tell you good news: that you as a Danish citizen in the UK actually have the right to vote in local elections,” Løkkegaard says in the video, before encouraging them to register and vote for the the Lib Dems, which he called the Liberals' "sister party".
“The are fighting for an ‘exit from Brexit', as it's called, and that's why it's so important that you get to vote for them in the local election, so that you can fight for your interests,” he said.
Local elections are being held on May 3 in all 32 London boroughs, as well as in Manchester, Leeds, Newcastle and Birmingham.
Løkkegaard told the Jyllands-Posten newspaper that he had agreed to front the video after being contacted by Liberal Democrat MPs, who are in the same group in the European Parliament as the Danish Liberals.
The Liberal Democrats hope that by informing Danes, Germans, Swedes and Spaniards that they have the right to vote in British local elections, they can make huge gains in their vote share.
“Traditionally, EU nationals don't tend to vote as they can't in national ones and don't always know that they can in local ballots,” Ed Davey, the Lib Dem MP in Kingston told the Financial Times (FT) earlier this week.
“So we are telling them that they can vote and how you do it. And by the way — if you don't like Brexit and you want to punish the government — vote for us.”
The FT published a graphic showing that EU nationals could boost the party's vote share by as much as 12 percentage points in some boroughs.
The Danish Liberal Party, despite its name, is firmly on the right of Danish politics, and perhaps closer ideologically to the British Conservative Party.
Løkkegaard told the Jyllands-Posten newspaper, which first reported on the advert, that although a reversal of Britain's decision to leave the European Union was “a tempting idea”, he personally feared it might be “wishful thinking”.