Majority of people polled believe Germany is dominating direction of European Union

Fine Gael voters are by far the strongest supporters of the treaty and are even more disciplined than Sinn Féin in backing the party line. Among Labour voters, however, a significant minority are in the No camp.

Among Fine Gael voters 74 per cent intend to vote Yes and 8 per cent No, while Labour voters back it by 46 per cent to 29 per cent. Fianna Fáil voters back the treaty by 50 per cent to 23 per cent, and Sinn Féin supporters reject it by 66 per cent to 13 per cent. Supporters of Independents and smaller parties are also against the treaty, by 41 per cent to 34 per cent. Green Party voters are also against.

In regional terms Dublin has swung behind the treaty since the last poll when the two sides were neck-and-neck in the capital. This time the Yes side is in the lead by 45 per cent to 29 per cent.

The Yes side is also ahead by 38 per cent to 28 per cent in Munster and the rest of Leinster. In Connacht and Ulster the margin is much tighter, with 39 per cent Yes and 36 per cent No.

As in the last Irish Times poll the Yes side has a strong lead among middle-class voters, but its lead among farmers has shrunk.

Among AB voters, the highest income bracket, 57 per cent are in favour of the treaty and 14 per cent are against. Among C1 middle-class voters 41 per cent are in favour and 28 per cent against.

Among lower-middle-class C2 voters the lead is smaller at 34 per cent to 31 per cent, and among the least well-off DE voters the No campaign is in the lead with 36 per cent to 31 per cent. There has been a big jump in the Yes support is this category.

Among farmers, 44 per cent are in favour, but the No side has jumped to 35 per cent.

People were also asked if they had voted in the last three EU referendums: 60 per cent of voters said they had; 18 per cent said they had voted in one or two; 18 per cent said they hadn’t voted in any of them. The DE social class were the least enthusiastic EU referendum voters with 51 per cent saying they voted in all three; farmers were the most likely to vote, and the best-off AB social class the next most likely.