Today (Friday, January 27) is the anniversary of the day that Allied forces liberated the Nazi death camp at Auschwitz-Birkenau.

For that reason it has been chosen as the date for this year's National Holocaust Memorial Day. In a debate last week in the House of Commons, MPs from all parties spoke about the importance of remembering the horror of Nazi genocide, especially as with each year that passes there are fewer survivors left to tell their story.

For me, the memory that sticks in my mind is discovering, when I was 11 or 12 that two boys in my class at school had fathers who had survived Auschwitz. I remember going to tea with one friend and his Dad pulling up his shirt sleeve to show the camp tattoo he still bore as a reminder never to forget.

Last year, on holiday in Prague, I walked round the old Jewish Quarter. I visited the oldest surviving synagogue in Europe, marvelled at the beauty of the Spanish synagogue and made myself study an exhibition of how a Jewish community which had been at the heart of Prague's civic life and culture for centuries was systematically persecuted and exterminated.

It is only two generations since Germany, seen by so many, including its own Jewish community, as the embodiment of European tolerance and civilisation, succumbed to the cancer of Nazism. It is to the credit of modern Germany that every child is taught in school about the horror of that past. That searing historical experience also helps explain why German leaders are mistrustful of nationalism and look to European identity and institutions to temper the excesses of national passions.

More recently still, we have seen the genocides in Cambodia and Rwanda, savage "ethnic cleansing" in Bosnia, and attempts in other countries too, to demonise and persecute people of a different race or religion.

Yet despite that, the passing of the years emboldens the holocaust deniers.

In my view, it is through deliberate remembrance that we both confront the horrors of the past and prepare ourselves mentally to rebut the deniers and challenge those who make light of racism today.

Let us never forget.