Prime Minister David Cameron urged young Britons on Thursday to make sure they vote in a June 23 referendum on membership of the European Union, warning that leaving the bloc would hit them the hardest.
With public opinion evenly split, youth voters are expected to play an important role in the referendum outcome because polling shows they are generally more pro-European, but less inclined to vote.
Cameron, who wants Britain to stay in the 28-country bloc, was speaking at the launch of a campaign targeted specifically at young voters.
"Whatever you do, June 23rd make sure you vote. It is your voice, it's your future, it's vital for you, vital for our country," he said.
The intervention is designed to increase voter turnout and thereby boost the prospects of a flagging "In" campaign which has ceded ground to eurosceptics in some recent opinion polls.
But polling shows younger voters tend to back the centre-left Labour party and Cameron has endured a difficult few weeks following a budget row, accusations of failing to protect British steel, and questions over his family's tax arrangements.
Low turnout was seen as one of the factors behind a defeat for the Dutch government on Wednesday in a referendum that rejected an EU treaty on deepening integration with Ukraine.
Asked about the outcome of that vote, Cameron said there were no direct comparisons with the British referendum.
'Most to gain, most to lose'
He argued that young people's job prospects would be disproportionately affected by the economic impact of an EU exit.
"You have the most to gain by staying in a reformed European Union and you also have the most to lose if we leave," he said.
Rival "Out" campaigners dismissed that claim, saying that money sent to Brussels under Britain's membership terms was adding to the national debt that would have to be paid off by young workers.
Eurosceptics were also angered by the government's decision to spend 9.3 million pounds ($13 million) on a 16-page leaflet setting out "why it believes that remaining in the EU is the best decision for the UK."
"This is not the facts, it is a misleading government propaganda campaign," said Vote Leave chairwoman Gisela Stuart.
The leaflet will be sent to every household in the country and promoted online to meet voter demand for more information on how to cast their ballot, the government said.