Opinium/ Observer 9 -12 April 2019

London4Europe Committee Member Michael Romberg works out what the opinion poll findings for the European Elections in London mean for seats. Remember: it’s just a poll – a snapshot that comes with a significant margin of error.

Data Source: Opinium / Observer - fieldwork 9-12 April 2019.  126 replies in London, only respondents certain to vote and after excluding don’t know/ won’t vote/ won’t say (13% of overall London sample)

This poll came before Labour's 2 May National Executive Committee meeting which is to decide  Labour's policy for the European Parliament elections. There have been polls saying that a failure to commit to a confirmatory referendum on any Brexit deal would cost Labour a huge number of votes. Over eighty MPs and MEPs - including London4Europe President Catherine West MP - have written to the NEC calling for a referendum on any deal. 

TABLE 1: This table takes the opinion poll findings and turns them into seats using the D’Hondt method (read more about that here). Seats won in each round are shown in bold. Poll numbers are then adjusted for subsequent rounds of seat allocation.

Notes

Brex = Farage’s Brexit Party

Ch = Change UK, formerly The Independent Group of MPs

Grn = Green Party

LD = Liberal Democrats

O = other

DK = don’t know/ won’t say/ won’t vote/ refuse to answer

On the allocation of the 8th seat, Labour's 9 is bigger than the Liberal Democrats' at the 3rd decimal place. Polls should not be relied on for his level of accuracy

CAVEATS

• It’s a poll. A snapshot in time. People’s views change. If “don’t know/ won’t say” is large, then their views could swamp small differences between parties once they decide.
• European elections normally have low turnout. Differential turnout amongst supporters of different parties could affect the result compared with a poll. Different polling companies have different methodologies for adjusting for turnout.
• The definition of “London” in the poll may not match the London polling region for the election.
• Polls come with a margin of error. On the highest level figures asking a question of the whole sample a rule of thumb is that polls come with a margin of +/- 3 percentage points (so 45% think this might be anything in the range 42%-48%). London figures are normally a subset of the poll so the margin of error is larger. A good sample size for a poll is 2,000 or so.

TABLE 2: this table works out a counterfactual allocation of seats if the Remain parties had joined on a single platform. The calculation assumes that the vote for the platform would be the sum of the votes for the individual parties. That would not be the case in real life – there are arguments for saying that a platform might do better or that it would do worse than the sum of the parties.

Remain = sum of poll results for Change UK, Green and Liberal Democrats

ADDITIONAL CAVEAT

• My calculations are on rounded numbers and that might introduce an error when results are close.