Both party leaders faced controversy prior to the campaign being suspended
Has the three-day break in campaigning by the political parties after the Manchester bombing helped or hindered Theresa May in the election? Or indeed Jeremy Corbyn?
Before campaigning was suspended in the early hours of Tuesday morning, the PM was being attacked over a social care u-turn and the Tory lead over Labour in opinion polls was narrowing.
The following three days inevitably saw Mrs May take centre stage: she chaired four COBRA emergency meetings, made three dramatic Downing Street statements and dashed to Manchester on a high-profile visit.
Bickering between politicians gave way to a sombre national mood. Constant images of battle buses, cheering activists and stump speeches were replaced by the PM’s podium and troops in Downing Street and Parliament.
‘Nothing has changed!’: May under fire over u-turn
A look at the front page splash headlines of the first and final editions of Tuesday’s newspapers after the bomb attack – which happened shortly after 10.30pm on Monday night – dramatically reveals the instant change in mood.
The Daily Telegraph changed from "Care cost chaos after May u-turn on key pledge" to "Manchester explosion kills 19 concertgoers"; the Daily Mirror from "How can we ever trust Mrs u-turn?" to "19 dead in pop concert ‘suicide bomb’".
The immediate impact of the suspension of campaigning – agreed by Mrs May and Mr Corbyn in a 4am phone call – was to stop the election campaign in its tracks.
A national crisis like a war or major terrorist attack usually has the effect of making leaders look statesmanlike.
And Mrs May’s allies would claim no modern PM has more experience of tackling terrorism than she has after six years as home secretary.
In the UK, the most obvious example of this type of poll bounce was Margaret Thatcher’s after the Falklands War in 1982, which transformed her fortunes from being hugely unpopular in 1981 to winning a majority of 144 in the General Election of 1983.
UKIP denies exploiting Manchester bombing
More recently, in 2015, the deeply unpopular French leader, Francois Hollande, saw a dramatic surge in his approval ratings over his response to terrorist attacks in Paris, though ultimately it wasn’t enough to save his presidency.
This week’s election campaign truce in the UK was impeccably observed and no senior figure in any of the mainstream political parties has accused the PM of seeking to exploit or capitalise on the Manchester bombing.
But as UKIP resumed campaigning a day early, deputy chairman Suzanne Evans said Mrs May "must bear some responsibility" for the attack. But then she also blamed immigration and the European Union. (UKIP blames the EU for most things.)
The truce didn’t just come when the Tories were getting bad headlines, though.
The suspension of campaigning came at a time when Jeremy Corbyn was facing an onslaught over his support for IRA bombers in the 1980s and ’90s.
Embarrassingly for the Labour leader, conspiracy theories peddled by left-wing mavericks about halting the campaign included one from the son of his top election strategist, former Communist Party member Andrew Murray.
Mr Murray’s 30-year-old son, Jack, said on Facebook the Manchester bombing had come "at an unbelievably ideal time" for Mrs May, before he was disowned by the Labour leader and his allies.
Sky asks Corbyn: Will you condemn the IRA?
One of Mr Corbyn’s closest allies, shadow home secretary Diane Abbott, was asked in a TV interview about troops on the streets and said: "I don’t want to engage in party politics."
But then she said: "If there is a need for troops to supplement armed officers then of course we accept that. But there will be some concern that these cuts in policing has meant we need troops now."
Cuts in police numbers were also attacked by the Police Federation, whose leaders said deploying the Army had exposed the cuts in police manpower imposed by Mrs May when she was home secretary.
So while her six years at the Home Office have given the PM vast experience in dealing with terrorism and security, her record there will now also come under renewed scrutiny in the wake of this week’s attack.
The last time political campaigning was suspended in the UK was after the murder of the Batley and Spen Labour MP Jo Cox exactly a week before the EU referendum last year.
Opinion polls immediately after her murder showed a surge for Remain and there were predictions that her death may halt the pro-Brexit momentum.
Well, we all know how wrong those forecasts were. Which is why we shouldn’t expect the three-day suspension of campaigning this week to have a big impact on the election result on 8 June.
There are still almost two weeks of campaigning left and the big TV election programmes – including The Battle for Number 10: May v Corbyn, on Sky News on Monday – are next week and could prove decisive.
Mrs May isn’t ready to resume campaigning yet, anyway. After attending the NATO summit in Brussels, she’s in Sicily for G7 and more talks on counter-terrorism with world leaders, doing her job as PM on the world stage.
And after bashing unpopular Brussels bureaucrats like Jean-Claude Juncker on Brexit in recent weeks, the US leaks of bombing evidence this week have given her an excuse to bash America’s pantomime villain, President Donald Trump, too.
One impact of the three-day suspension of campaigning, however, is that we haven’t heard Mrs May say "strong and stable" since Monday. Maybe we’ll hear it less often between now and 8 June.
Why? First, because it rings hollow after the embarrassing social care u-turn.
And second because it might sound like she was attempting to exploit the Manchester bomb attack, which many voters would find distasteful.
Another possibility is that the tone of the election campaign from now on might be a bit more respectful and less brutal, with fewer personal attacks, after the tragedy at the Manchester Arena.
That may be true for the first few days after the resumption of campaigning. But – barring any more tragic incidents like Manchester – a more civilised campaign is unlikely to last until polling day!
:: Sky is hosting the first live studio audience Q&A of the election with Theresa May and Jeremy Corbyn. Watch Sky News: The Battle For Number 10 on Bank Holiday Monday, 29 May, at 8.30pm.