The final days of political campaigns are traditionally when voters fully tune into the furore and decide who they will support.
It should be no surprise then that, with just days to go until Friday's ballot box date, the past 24 hours have seen the heat turn up dramatically in the presidential race.
In a blunt and uncharacteristically aggressive attack on Ms Connolly's credentials this weekend, Ms Humphreys stepped away from the until now relatively polite discord of the campaign to date to lay the boot into her presidential rival.
"When I look back at my time as a Credit Union manager, I'm different to Catherine because before Catherine got into politics and before I got into politics, she was working for UK banks to repossess Irish homes.
"I was working as a Credit Union manager and I was trying to help people with huge financial difficulties, and I was trying to keep them in their homes," Ms Humphreys told the newspaper.
That attack was repeated by Ms Humphreys at a canvass in Athlone, Co Westmeath this afternoon, where the Fine Gael candidate said her rival needs to clarify how many homes were involved, how many were family homes and how much she was paid for the work.
Clearly singing from same hymn sheet, or at least reading from the same carefully targeted press release, Fine Gael TD and Education Minister Helen McEntee later repeated the comment to RTÉ Radio's This Week radio programme, telling presenter Samantha Libreri: "I am not saying that Catherine Connolly did anything incorrect in her career as a barrister, but she has come into the Dáil and castigated those same banks and people that she worked for in repossession cases."
None of that campaign confrontation should be any surprise to political anoraks who were waiting for the mud-slinging to increase in force in these final days of the race.
And nor should anyone be surprised by Catherine Connolly's equally firm response, the Independent candidate telling RTÉ's Paschal Sheehy that the Fine Gael attack strategy is "a new low".
"Certainly, the campaign has reached a new low by Fine Gael. Absolutely, a new low.
"This is a new low and I am just going to keep going until Thursday [the final day of campaigning before Friday's vote], building on the momentum that is there.
"The momentum has been there since July and it has been building in intensity all the time. Certainly, I will let the people of Ireland decide and that is really the important thing."
Asked by RTÉ News if she wanted to address the substantive point about her representing banks in home repossession cases during the property crash, Ms Connolly said: "I have addressed this over and over again and for the candidate for the presidency to misuse that in the way that she has is just a new low. It's just a new low."
Hours later, Fine Gael this evening posted what critics have described as an attack video - again on the same topic - on social media, saying they believe Catherine Connolly has questions to answer.
'Irish voters won't approve of this kind of negative campaigning'
That decision was heavily criticised by Ms Connolly's campaign team, including Social Democrats TD and party co-ordinator with the Connolly campaign Jennifer Whitmore, who told RTÉ: "We have concerns about the negative campaigning we are seeing, it would appear to be straight out of the playbook of US politics.
"Irish voters won't approve of this kind of negative campaigning."
Regardless of the clear division on the subject, both sides of the campaign will no doubt agree on four key points to watch out for in the final days of the race.
The first is what developments may come from the repossessions story Fine Gael is continuing to push, and what answers Catherine Connolly provides to the core points of fact within it.
The second is Tuesday's Prime Time debate, which is the final debate of the presidential campaign and will no undoubtedly be dominated by the campaign clashes of recent days.
For its own unique reasons, the impact of the final TV debate in the 2011 campaign was seismic, but it is not the only final campaign to have had a genuine impact, something both the Humphreys and Connolly camps will be all too aware of.
A third point to watch closely will be where Fianna Fáil's vote now goes.
Officially of course, Jim Gavin remains a formal presidential candidate as he stepped out after the nominations process closed - meaning while he can withdraw from campaigning, he continues to officially be a candidate on the ballot.
Government chief whip Mary Butler told RTE's The Week In Politics she will vote for Heather Humphreys, joining the likes of Environment Minister Darragh O'Brien and Taoiseach Micheal Martin in that position, as well as former taoiseach Bertie Ahern and 2011 and 2018 Independent presidential candidate Seán Gallagher who yesterday asked his "friends" in Fianna Fáil to back Fine Gael.
But six Fianna Fáil TDs - Tom Brabazon, Peter 'Chap' Cleere, Padraig O Sullivan, Cathal Crowe, Erin McGreehan and Malcolm Byrne - have also confirmed they will still vote for Mr Gavin, for reasons ranging from loyalty to the official candidate to presumably sending a message to more senior party ranks after the decisions which led to Fianna Fáil's own disastrous campaign.
And that split does seem to reflect the Fianna Fáil grassroots view, with opinion polls suggesting there is at this stage still a division within supporters over whether to sit the election out, vote in solidarity with Jim Gavin to make a point, back the left candidate Catherine Connolly or back the middle ground Heather Humphreys - thereby potentially seeing Fianna Fáil help Fine Gael to its first ever presidency.
For now, the latest opinion polls - which it must be remembered are a few days old - are consistently suggesting Catherine Connolly has a formidable lead.
Indeed, last week's Irish Times/Behaviour & Attitudes poll placed Catherine Connolly on 38%, Heather Humphreys on 20% and Jim Gavin on 5%.
That, though brings us to the final point to keep within eyesight, namely whether those poll numbers translate into real votes - and on what side of the divide the 18% of undecided voters and the 12% who may not vote will fall.
While there are rumours of a final opinion poll in the middle of this week, the actual decisions won't be made until voters go to the ballot box on Friday.
With much at stake, don't expect a quiet and polite political discourse in the days to come.
