THE murderous attack in London on Saturday night, hot on the heels of the Manchester concert bombing, has pushed security and the terrorist threat to the top of the agenda in these closing days of the election campaign.
The sadness, shock and outrage at these terrible incidents brings people together, but also raises serious questions for politicians.
Public concern about national security and issues of law and order normally tend to benefit parties on the right rather than the left, but it is not always the case.
And Theresa May has been left having to answer criticism over large cuts in overall police numbers and specifically in armed officers during her time as Home Secretary.
Mrs May insists she has protected the budgets for counter-terror and security services. But police representatives have warned the cuts mean the UK is less able to prevent the sort of terror attacks that have now been seen three times in the past three months.
The London and Manchester attacks bring tragedy to the heart of what was already proving an eventful and unpredictable election.
Mrs May called it in the hope of strengthening her position by increasing her majority from 12 to over 100. But the campaign has not gone well for her.
Despite hiring Australian guru Sir Lynton Crosby, nicknamed the Wizard of Oz, the Tories have seen their lead in the polls steadily fall as they alienated their natural supporters with the so-called dementia tax, removal of the “triple lock” on pensions and scrapping universal winter fuel payments.
The Prime Minister’s much-mocked mantra about “strong and stable leadership” was undermined by her social care U-turn. And they failed to say anything useful about Brexit, which was supposed to be the central issue of the election. Even Tory activists are describing it as “the worst campaign we’ve ever run”.
If Mrs May is returned to Downing Street without a significantly increased majority, she will be weaker and more vulnerable to challenge.
In contrast, Jeremy Corbyn was written off by commentators long before the election campaign even began, but has seen Labour’s poll ratings rise to such an extent the party is now neck and neck with the Tories in one poll.
If Labour secures anything like the 40 per cent suggested by the Survation survey, Mr Corbyn will have done better than Ed Miliband in 2015 (30.4 per cent) or Gordon Brown in 2010 (29 per cent) or even Tony Blair in 2005 (35.2 per cent).
His critics inside the party would find it difficult to mount a challenge to his leadership. And they might even face claims that if they had backed him instead of attacking him, Labour could have won.
The SNP’s unprecedented success in 2015, winning 56 out of 59 Scottish seats, means the party is almost bound to end up with fewer MPs after tomorrow. But even if they drop below 50, they will still clearly have many more than any other party and will therefore be entitled to proclaim themselves winners.
Significant Nationalist losses, however, will raise concerns for the future, both about the level of support for independence in a second referendum and the SNP’s prospects at the 2021 Holyrood elections.
Much is at stake at the ballot box tomorrow for all parties – and for all of us. Don’t forget to vote.