It follows a string of polls over recent years which have given comfortable leads to the pro-European camp. Significantly, it is the first measure of public opinion since the Government changed the wording of the referendum question, lending weight to claims that the new phrasing boosts the chances of victory for the ‘Out’ campaign. 

The survey also found strong backing for David Cameron’s stance in standing up to German Chancellor Angela Merkel, who wants the UK to take in a greater share of migrants.

Growing public support to cut all ties with Brussels came as it was revealed the Prime Minister told Merkel to her face: ‘I could walk away from the EU.’

At a private dinner in Downing Street, Merkel accused him of being ‘too forceful’ in demanding concessions from the rest of the EU. That was why ‘we all hate you and isolate you,’ she said.