That is according to a Eurobarometer survey about to be released by the European Commission.
It predicts record abstention of 66 percent. The the survey says participation will be even weaker in some countries, the poorest in Poland, Austria and the UK.
Eight out of ten British voters could not even name the date — Thursday 4 June for them, coinciding with local elections, and up to June 8 in other countries.
The lack of awareness is general. The strongest showing is expected to be in Belgium and Luxembourg, where voting is compulsory by law.
Media disinterest in the campaigning and the core subjects is said to be crushing, to the point of hostile in France, Britain and Belgium.
Economic concerns combined with ignorance is therefore seen as undermining trust in the EU’s institutions.
More than half the people who took part in the January-February Eurobarometer poll wanted the EU election campaign to focus on employment and growth. Pensions, crime, immigration and terrorism trailed far behind.