The Labour politician reflects on two cities that shaped his world - Rome and his beloved Sheffield
As a child I believed that my father was a clerk in the Termini station in Rome and when he spoke of his time there he always talked about this extraordinary church called Santa Maria Maggiore. I later found to my amazement that he had been a Catholic priest and that his years in Rome had been spent not as a clerk in Termini station but as a priest at the Gregorian University.

The summer after my father died I went to Rome to see the Church. Although I have absolutely no religion at all - I'm an atheist - this church seemed to me to be the most extraordinary manifestation of belief and faith imaginable. I guess it was because my father talked to me about it so much, but I could imagine how he felt as a young man in Rome. It did not convert me to Christianity. It didn't convert me to anything. But it helped me to understand why this great spiritual experience comes about, and why it's so important to some people.

My father and I were great friends until the day he died. I always found him to be a very gentle self-effacing sort of person who allowed himself to be the junior partner in the marriage with my mother. So I never thought of him to have done such an immensely heroic thing as leave the Catholic church, in 1928, and run off with a political activist (my mother). I just wish I'd known about it, as I'd thought about my father as a lot of admirable things, but not a hero. I guess he didn't want me to know because he was embarrassed about the deception, and he and my mother hadn't been able to get married straight away. They hadn't been married when I was born. But it was just a misjudgement on his part and I'm very proud that he did it and got on with it.

Every time I go to Rome I go to see Santa Maria Maggiore. There is no foreign destination that has the same effect on me. I'm very Audrey Hepburn about it and tend to say, as she did in Roman Holiday when asked which of the European cities she had enjoyed the most: "Rome, Rome and definitely Rome." But I wouldn't want to live there.

At the end of JB Priestley's English Journey he says that if he had to have a holiday in either the Black Country or Tuscany it would undoubtedly be Tuscany, but if he had to choose a home he would most certainly make his way to Wolverhampton. I feel rather like that about my home, Sheffield. That the men who were boys when I was a boy will sit and drink with me is very powerful. My mother still lives in the house I grew up in. To my shame, I was born on the Sheffield United side of Sheffield, but I first saw the light of day on the Sheffield Wednesday side. If you asked me where was the place that made me, it would be Sheffield. I am what I am because of that city and the Labour Party.

I'm going to Rome for a day tomorrow and I shall go and see the church, but I must come back as quickly as possible because of my dog, Buster, who keeps me in the UK. I'm in favour of passports for pets but I would not dream of taking Buster with me. There is no joy for Buster in travelling across France over the Alps in a hot motor car for a fortnight, or going in an aeroplane in a dog box. I think it would be wrong to take him away for a holiday with difficult travel arrangements. But for people who have to live abroad I think passports for pets are quite right. So I don't get to Italy much. If you asked me to write 10,000 words on "The Dog That Changed Me", I wouldn't have a problem.

"Buster's Diaries", as told by Lord Hattersley (Little, Brown, pounds 4.99), is also available on audio (BBC Worldwide, pounds 8.99).