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Professor Howard

A leading Oxford University professor has concluded that it was very likely that the advertising overspend on Facebook by Vote Leave in the last days of the EU Referendum campaign in 2016 changed the outcome.

Professor Philip N. Howard, Director of the Oxford Internet Institute, a Professor of Internet Studies and a Fellow at Balliol College at the University of Oxford, studied the digital campaign strategy and practices of Vote Leave and its impact on voter behaviour. He relied on materials disclosed by Facebook to the parliamentary committee investigating Fake News and publicly available accounts written by campaign insiders.

Howard has provided an expert’s report to the claimants in the UK in EU Challenge judicial review. He concludes that Vote Leave reached tens of millions of people over the last few days of the campaign as a result of Facebook advertising purchased in excess of its statutory spending limit.

Croft Solicitors, which is acting on behalf of the UK in EU Challenge claimants, have now asked the High Court for permission to use the report as evidence at a hearing in the High Court on Friday 7th December.

Professor Howard said: “Having studied its digital campaign in line with voter psychology and behaviour, my professional opinion is that it is very likely that the excessive spending by Vote Leave altered the result of the Referendum.

“A swing of just 634,751 people would have been enough to secure victory for Remain. Given the scale of the online advertising achieved with the excess spending combined with conservative estimates on voter modelling, I estimate that Vote Leave converted the voting intentions of over 800,000 voters in the final days of the campaign as a result of the overspend.”

The Vote Leave campaign should have stopped its digital advertising when it passed its spending limit some time on the afternoon on Tuesday 21 June 2016 – two days before the Referendum vote took place on 23 June.

The pro-remain Stronger In campaign was forced to stop its digital advertising on the last day of the EU Referendum campaign because it had reached its spending limit.

Many voters make up their minds in the last few days of election and referendum campaigns. According to studies by the London School of Economics and Opinium, between 20% and 30% make up or change their minds within a week of the vote, with half of those individuals doing so on election day itself.

Drawing upon a range of data sources, Professor Howard’s report concludes that it is very likely that the overspending of Vote Leave, which enabled it to target voters for two extra days on the run up to the Referendum, altered the result in its favour.

Those behind the UK in EU Challenge are asking the High Court to rule that illegal campaign spending during the course of the Referendum means the result cannot now be considered the ‘will of the people’ and therefore the Brexit process should be halted.

Carole-Anne Richards, one of the UK in EU Challenge claimants, said: “Members of the public should be able to rely on the fact that the process behind any vote, not least one so far-reaching for the UK, is carried out lawfully, free from corrupt and illegal practices. This is clearly not the case here.

“We are very grateful to Professor Howard for his work in looking at Vote Leave Facebook advertising overspend and correlating that with voter behaviour. Anything that sheds light on what took place, especially where illegalities have been proven, is to be welcomed and should be made available in the public interest.”

Rupert Croft of Croft Solicitors, which also acted on the claimants’ side in the successful Gina Miller Article 50 proceedings, commented: “The claimants contend that it’s essential that Parliament understands the legal and constitutional status of the result of the Referendum.

“The serious breaches of electoral law that have recently come to light have cast doubt on the legitimacy on the Referendum result. Parliament is entitled to have the guidance of the Court as to the correct legal position. This case should enable that.”

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Notes to editors:
Professor Howard’s report is confined to Vote Leave and BeLeave overspending as currently identified by the Electoral Commission. Please see the report for further details:

LSE and Opinium poll:

The Oral Hearing takes place at the High Court on Friday 7th December. Follow the latest updates here:

Media contact:
Sarah Hall at Sarah Hall Consulting Ltd on 0702 162 704 /