For many television viewers George Alagiah has become a friendly face as they kick back at the end of their working day.

As the presenter of the BBC's News at Six, he's become a familiar part of all our lives, and he received an affectionate welcome from the audience of about 400 people who gathered to hear him talk at Red Maids' School in Westbury-on-Trym on Friday night.

But anyone who was expecting a light-hearted evening, with amusing tales about the life of a broadcast journalist and gossip from the newsroom, was in for a surprise.

Mr Alagiah, who received an OBE last year for his services to journalism, chose to use the occasion to cast off his usual BBC objectivity, and give his very personal opinions about immigration.

"Multiculturism has, in some places, delivered exactly the opposite of what it was designed to create," he said.

"Some areas have become distinctive by entire communities that have developed into an enclave, based entirely on their place of origin.

"I've been to certain places, Bradford for example, where it feels like I'm reporting from a foreign country.

"In that city, they even have linking projects to bring together white children from the white neighbourhoods, with Asian children from the Asian neighbourhoods. They bus one group of children across the city, just so they get to interact with the others.

"Linking projects were something I remember reporting on in South Africa, as the country was trying to come out of hundreds of years of institutionalised racism, but this is in England after 40 years of supposed multiculturalism. Something has clearly gone wrong with the dream of multiculturalism."

Mr Alagiah gives to the Beeb an air of trustworthiness and gravitas; a sense of familiarity without the injection of undue personality, and an endless reserve of calm professionalism. He has become emblematic of a typically British news reading persona – despite the fact his roots are far from English.

Born in Sri Lanka in 1955, his primary education was in Ghana, where his parents moved in 1961. He attended secondary school at St John's College in Portsmouth, and later Durham University.

"I felt I had to become British when I first arrived here," he said. "Today we should be saying to immigrants: welcome to our country, but what will you do for us? What can you contribute?

"I think if we start to ask that question of immigrants, you might feel you would prefer to have them here, rather than those who have their Britishness as a birthright, but fail to live up to the responsibilities with it."

The former foreign correspondent added: "My story epitomises what I call the magic of migration. If you had told my parents 50 years ago their little boy would grow up to become a senior BBC journalist, they would have laughed, because in those days it wouldn't have been possible.

"That's how I know we've come a long way towards a multicultural society, but it's a dream that needs working on.

"It lost its way in the Seventies and Eighties because anyone who created a debate about it was branded a racist.

"I think people are beginning to realise it's a debate that you can have without it descending into racism."