Lord Rogers, who has been a key figure in advising the Labour Party on architecture for some years, told the Lords we should be regenerating derelict land and unoccupied buildings in our cities "into clusters of compact, live-and-work communities based on walking, cycling and rapid public transport networks".
Rather than sprawl, he said, we should make better use of the space within our cities. Even in London, he added, 5 per cent of the land is derelict or unused.
He said that effective public transport was one key to a better city, inspiring public places were another. "But in Britain's cities today, the public realm has suffered severe erosion - by the car, and by a lack of public ambition. There have been no major public squares, tree-lined avenues or parks built in central London in our lifetimes.
"We have a choice. Roundabouts or civic spaces? Highways or riverside parks? Elitist clubs or open public institutions?
"Why not use Millennium Lottery funds to plant a million urban trees? Why not create the most beautiful riverside park along the Embankment from here [Westminster] to Blackfriars? Why not approach this, the Mother of Parliaments through a noble square - rather than across a congested roundabout?"
Lord Rogers detailed what he felt was "wasteful, inefficient and brutalising" in our cities.
He said: "We can ignore the figures about increasing inequality; but it is harder to ignore huddled figures sleeping in streets and doorways or trapped in decaying housing estates. We may flee from inner-city dereliction and take to the suburbs, but in so doing we extend the urban sprawl into the countryside. We may bemoan the decline in public transport while we sit in our cars and poison the air; but meanwhile, urban air quality continues to decline, one in seven of our inner-city children suffers from asthma.
"In London, we've built more and more roads, yet they carry almost 50 per cent fewer people than in 1956, because fewer people take the bus and more go by car. As a result, the average speed has dropped to the horse-and-carriage rate of a century ago. The wasted time is said to cost London pounds 15bn a year in wasted time and resources."
On public buildings, Lord Rogers said we must ensure that schools, hospitals, universities, public housing projects, parks and squares are designed by the best talent and sometimes by "the most adventurous". The education system should promote an understanding of the urban environment, he said.
Lord Rogers added: "Cities have the power to humanise or to brutalise. They are made by people and people get the cities they deserve."