Murder brings the debating to a halt amid utter disbelief
By early morning, crowds of tourists from all over the world had eagerly gathered on the lawn at Westminster, drinking in the iconic vista of Big Ben - the hulking bronze statue of Winston Churchill in his overcoat, casting a watchful eye on the scene below.
It was a fitting snapshot of the situation one week out from Britain's EU referendum, with the eyes of the wider world eagerly trained on the UK as it approaches the biggest decision in a generation.
This was just hours before the vicious murder of Jo Cox (41), a Yorkshire MP, which left the country stunned.
Cox was shot and stabbed repeatedly by Thomas Mair (52), who reportedly shouted "Britain first" as he attacked her in broad daylight.
As tributes began to flood in and the country tried to make sense of what had happened, Cox's husband Brendan urged people "to unite to fight against the hatred that killed her".
Before this tragedy emerged, campaigners had been out in force. Headlines at the news stands screamed a dramatic surge for Brexit in the latest polls.
Ten Ukip poster vans were touring London, warning of a 'Breaking Point' and picturing a straggling queue of exhausted migrants who had flocked from war-torn countries - although eagle-eyed commentators pointed out that the photograph was taken last year in Slovenia, not Britain.
At lunchtime, a boardroom at the offices of a London law firm, Bircham Dyson Bell, was filled with around 80 entrepreneurs and investors who had gathered for the launch of The Entrepreneurs Network's 'annual Parliamentary Snapshot' with a panel discussion on Brexit.
It was a very plummy affair - though bags of crisps were ravenously scoffed amid the discussion, regardless of the Savile Row suits. Quintessential Tory MP, Jacob Rees-Mogg was the plummiest of them all and told the attendees that the people forecasting doom and gloom were "using the wrong models.
"Whether right or wrong, many people will be voting on emigration," he added.
The overall feeling was that the 'Leavers' had it - but there was an air of great trepidation in the room.
Far from wanting to stem immigration, these business leaders are fearful that it will become impossible to recruit the highly skilled workers that they so badly need.
One of the attendees was Rupert Gather, chairman of InvestUk Ltd, whose pro- 'Remain' son, Felix (18), has just completed his first year in medical studies at Trinity College Dublin.
"I'm very much a Leaver," said Rupert of his own stance in the referendum - but admitted that Felix had told him he was "about to be hoist on my own petard" because with Felix's fees at Trinity currently around €1,800, as a 'foreign' non-EU student, they would be considerably more - at a possible €20,000, Rupert believes. But Felix had also pointed out something interesting.
Just like the professional soccer players, he may be entitled to benefit from the 'Granny' rule and because he has an Irish grandmother, he could apply for an Irish passport and so maybe keep his fees at the EU level.
"Now he's looking for his cut for saving me €100,000," laughed Rupert.
Irish PR guru Rory Godson, who is involved with the Irish for Europe campaign, admitted that he was deeply concerned about the prospect of a Leave result. His Powerscourt communications company employs 35 people in London and "three or four" in Dublin.
"I don't think the short-term consequences for us will be bad but on a long-term basis, it's not good," he said.
Brexit was the topic on the lips of a very different gathering in Camden.
In the lobby of the London Irish Centre, a group of young women were eating comforting slices of traditional brown bread, while upstairs, John Halligan chaired a round-table EU debate for elderly people.
The discussion was robust and most came around to the minister's plea to stay in the union. Nevertheless, some undecideds remained.
Bridget Walsh (75), formerly of Athlone, Co Westmeath, said it was the NHS waiting lists which concerned her.
But Phyllis Morgan (71), who works with the Irish Women's Survivors Network - she was reared in mother and baby homes and went to London aged 18 - revealed that despite her early hardship she "cannot stop thinking of Ireland" and how it might suffer if the UK left.
Moments after leaving, the minister was back, with the devastating news of the shooting. The campaign was suspended.