The survey says the Socialists will win 142 seats, well ahead of the next best placed group, ALDE, with 72 seats.
The survey, the latest in a series by Parliament, is based on a cross-section of national polls on the composition of the next Parliament. The predictions are based on polling data published in EU Member States until 26 March.
Parties are only allocated to existing political groups or where they are already affiliated to an associated European political party.
All new political parties and movements that have not yet declared their intentions are categorised as “other”. Those classed as “other” will number 52, says the survey.
The next Parliament will have fewer MEPs (705) than the outgoing Parliament (751) and the elections will take place from 23-26 May. Many expect an influx of members from so-called populist and nationalist parties.
Meanwhile, another separate poll says that emigration and domestic issues, such as corruption, the cost of living, health, housing, and unemployment, currently feature prominently among voters.
Corruption is cited as a major domestic issue in Greece (by 78 percent of voters), Hungary (72 percent), Italy (70 percent), Slovakia (68 percen), Spain (74 percent) and Romania (69 percent).
“The findings from this poll should give heart to pro-Europeans and show that there are still votes to be won on major issues such as climate change, healthcare, housing, and living standards” Mark Leonard, Director of the European Council on Foreign Relations
The poll, carried out by YouGov across 14 European Union Member States covering 80 percent of the seats in the Parliament, is said to provide a snapshot of opinion across major issues.
It also suggests that, despite efforts by some parties to “frame” the European Parliament elections as a referendum on migration, voters in the Czech Republic, Italy, Poland, Romania and Spain are more concerned about people leaving their country than coming in.
On other issues, such as economic performance and climate change, the poll shows that voters are generally pessimistic about the strength of their national economies, and that there are majorities in 13 of the 14 polled Member States for the introduction of greater protections for the environment - even at the cost of impacting economic growth.
Mark Leonard, Director of the European Council on Foreign Relations, said, “The EU elections have been sold as a battleground over the heart of Europe. Viktor Orban, Matteo Salvini and Steve Bannon have tried to turn the election into a referendum on migration, mobilising a sovereigntist coalition to dismantle the EU from inside.”
“The findings from this poll should give heart to pro-Europeans and show that there are still votes to be won on major issues such as climate change, healthcare, housing, and living standards. They will be making a strategic blunder if they accept the framing of the anti-European parties that this election will be won or lost on migration alone.”
Leonard continued, “To mobilise these voter constituencies, though, pro-European parties need to provide a serious and honest assessment of the EU’s failings. They must be international and outward-looking reformers, who will speak and act for Europe’s moderate majority.”
The poll showed a general consensus in Western Europe that refugees should be more fairly distributed across Member States, with the key countries affected by the 2015 migration crisis, such as Germany, Greece, Italy, Netherlands and Sweden, most supportive of this policy proposal.
Just 21 percent of French voters see immigration as a significant issue facing the country, with the cost of living topping the poll at 36 percent.
Despite strong anti-immigration rhetoric from administrations in Hungary and Poland, only 19 percent and 7 percent of voters in each country identify immigration as a core issue.
In Germany just 25 percent of voters think that migration has had a negative impact on their wages.
German voters are generally split down the middle on the benefits of economic migration - with 39 percent in favour of addressing skill deficits with foreign talent, and 42 percent against.
The poll forms part of a pan-European project by ECFR to understand the wants of voters ahead of this year’s elections.