Pollsters are having an industry-wide row over EU referendum poll accuracy

There is debate about which polls are telling the truth

The Royal College of Physicians has warned Brexit could harm patient care and public health, in a major intervention in the EU referendum debate (iStock)

The polling industry has descended into a row about what the real state of play in the EU referendum race is – as different firms show wildly differing results.

Polls conducted over the phone are consistently showing significant leads for the Remain campaign, but online polls are showing a much tighter race – practically neck-and-neck.

Peter Kellner, former president of YouGov until this year, said his old firm was currently getting the race wrong because it only conducted online polls. He said these surveys included too many Ukip voters.

“On the great majority of issues, online and telephone polls produce comparable results,” he said.

“However, the EU referendum is one of that minority of occasions when there is a significant difference; so far, telephone polls seem to generate more accurate results.

“We shall see whether the online polls acknowledge this and make further changes to their methods.”

But told of the comments, Stephan Shakespeare, the CEO and founder of YouGov, replied: “Is this the same Peter Kellner who got [the 2015 general election] wrong? Which we've fixed...”

YouGov’s chief innovation officer Andy Morris hit back even harder – claiming in a blog post that it was in fact telephone polls that were flawed because they included too many graduate voters.

“The online polls are doing a better job of finding representative samples and therefore a better job of representing the views of the population,” he argued.

In December the pollster ComRes, which conducts both phone and online polls, said its phone polls were more accurate. The latest ComRes phone poll had figures of 52 per cent voting to remain but 41 per cent voting to leave.

The back-and-forth comes after the industry disastrously failed to judge the result of the 2015 general election, leading to an industry-wide review of practices.

Telephone polls have a better record than online when it comes to UK-wide referendums.

According to an analysis by the Political Betting website online polls got the 2011 AV referendum wrong by an average of 14.8 per cent, while phone polls were only 1.9 per cent out.

The EU referendum will be held on 23 June.