The light-hearted fun that dominated Wednesday's campaign following the "battle of the Thames" between Nigel Farage and Bob Geldof swiftly turned to horror yesterday.
The shocking attack on Labour MP Jo Cox which led to the death of the 41-year-old mother of two overshadowed yesterday's referendum campaign, as a stunned nation came to terms with the events.
News of the attack filtered through on social media and local media channels just as many people were taking a break from work to watch the England v Wales match in the Euro 2016 football championships.
By the time people were beginning their evening commute, the news of her death was confirmed.
The shocking developments prompted all sides in the referendum to break off campaigning for the rest of the day.
The broader impact of the brutal attack on the rest of the campaign remains to be seen. Police are investigating claims that the assailant shouted “Britain First”, a possible reference to the far-right political party.
So far, there is no suggestion of any link with Islamic terrorism – there were unconfirmed reports that the assailant was a white man in his early 50s.
What is becoming clear, however, is that Britain is increasingly divided on the EU question.
With just a week left before the referendum, yet another poll showed a six-point lead for the Leave campaign.
The poll by the Evening Standard newspaper found that 53 per cent of voters were in favour of leaving the EU, with 47 per cent wanting to stay.
While the exclusion of “don’t knows” from the results will offer some hope to the Remain campaign, the underlying findings of the poll are more worrying. It found that immigration has now overtaken economics as voters’ main concern.
The Remain campaign is desperate to keep the economic arguments on the agenda, but communicating its message is another matter.
George Osborne’s warning of a “Brexit budget”, should Britain vote to leave, appears to have backfired given the backlash from Labour and Conservative backbenchers.
Similarly, a fresh warning by the Bank of England yesterday about the economic risks of an out vote, was obscured by a row between the governor of the Central Bank Mark Carney and the Leave campaign after four prominent Brexiteers – Nigel Lawson, Norman Lamont, Michael Howard and Iain Duncan Smith – criticised the "woeful failure" of the bank to present a fair analysis of a British exit.
Ensuring that voters engage with the economic arguments in the coming week will be a tough challenge.
The Remain campaign may find that Michael Gove’s warning last week that “people in this country have had enough of experts” may prove prescient.