Seventy-nine years ago, in 1939, he was one of 669 frightened children, most of them Jewish, bundled onto a train and spirited out of Nazi-occupied Czechoslovakia in an operation organised by the British diplomat Nicholas Winton.
Alf was only six when he arrived in Britain. His exemplary record of public service, which continues as a Labour peer, has been a lifelong act of gratitude to the country which cared enough to take him in, along with thousands of others who would almost certainly have been murdered, and offer sanctuary.
So when Lord Dubs launched a campaign for greater compassion in politics at the weekend, he brought to it a degree of moral authority unrivalled by any other British politician, irrespective of party.
That alone should ensure that his call for greater tolerance and a less hate-filled tone of public discourse is heeded. He knows where fanaticism leads. Childhood friends left behind in Prague became its victims.
And Britain has seen where it leads too. The murder of Batley and Spen MP Jo Cox in 2016 by a right-wing extremist was the most shocking and tragic example of what an increasingly polarised and vicious atmosphere surrounding politics can result in.
Yet even such a horrifying act has done nothing to reduce the amount of bile being spewed at, and between, politicians. We have reached the worrying stage that those who disagree no longer see each other as opponents to be debated with, but enemies to be crushed.
There is cross-party support for Lord Dubs’ campaign, but whether it succeeds is far from certain. The tone of debate in Britain has become coarse, confrontational and threatening.
Three days before his campaign was launched, a fellow peer, Yorkshire-born Eric Pickles, spoke thoughtfully in the Lords about the shocking level of hate crimes being recorded, more than 94,000, and highlighted how entrenched such behaviour is becoming.
He had tweeted about visiting the former Nazi concentration camp at Treblinka and was immediately targeted by a Holocaust denier insisting that it had not been a place of mass murder.
Such lies are rife on the internet, and the hatred of which they are a part is endemic. It seems barely credible that in 2018, we should be seeing widespread unease in the Jewish community about the degree of anti-Semitism in Labour, or that other racial or religious groups should worry for their safety.
That they do ought to be a cause of national concern, as should the fact that female MPs are the targets of vicious and frightening levels of intimidation, with threats of rape on social media.
The rise of forums, including Twitter and Facebook, have fuelled this tendency towards extreme behaviour. By enabling the abusive to reach out directly to their victims in an instant, social media has emboldened them.
And some politicians have, whether deliberately or not, contributed to the coarsening of debate. The starting point for the current levels of abuse was the 2014 referendum on Scottish independence.
Nationalists engaged in a disgraceful level of intimidation, both online and in person, with at one point the then Labour leader, Ed Miliband, and his shadow cabinet appearing genuinely alarmed for their safety when confronted by a baying mob.
That campaign normalised abuse as a political tactic and weaponised social media as a means for hurling it. A line was crossed, and it was no surprise that the Brexit campaign two years later was the most divisive and bitter in modern British history, with the rancour of point-scoring often drowning out sensible and rational debate.
If anything, matters have become even worse since then. As uncertainty continues to surround how leaving the EU will work in practice, the degree of hostility between rival factions only grows more intense.
Within the Conservatives, those of opposing views exhibit an undisguised loathing of each other. This is not mature politics conducted by sensible, intelligent people, which is what the country has every right to expect, but more akin to a tribal blood feud.
Lord Dubs, at 85, has a lifetime of experience behind him and is surely right when he says that the nastiness has to be somehow taken out of public discourse. Tolerance and respect for others are the core virtues of this country, which he gratefully made his own, but they are being undermined by a political class that should be upholding them.
Abuse has to be stamped out of public life, or the level of its viciousness will only continue to grow and eventually smother proper debate. Cracking down on its proliferation on social media won’t be easy, but politicians can take a lead by getting out of the gutter and aspiring to the standards of behaviour exemplified by Lord Dubs.