Oxford author Philip Pullman compared the Jericho canalside with the beauty of Venice today in a bid to stop a flats development getting the go-ahead.

Last year the city council turned down Spring Residential's plan to build 54 one- and two-bedroom flats and a boat repair berth on the former Castle Mill boatyard site.

This week, a Government planning inspector has been conducting an inquiry following the developer's appeal and on Tuesday, Mr Pullman, the author of the award-winning His Dark Materials, led protests by about 200 people outside Oxford Town Hall.

Yesterday, he returned to the town hall's Old Library, where the inquiry is being held, to make an impassioned plea against the development.

The 62-year-old, who lives in Cumnor, told planning inspector Ava Wood that a Canaletto painting in the Ashmolean Museum featured a canal scene in Venice, showing people at work, sunlight on the water and a church in the background with a tower.

Mr Pullman said: "It's an everyday scene, on a human scale, where everything fits and all these different activities have their place and their dignity and their beauty.

"That painting is guarded night and day and insured, no doubt, for hundreds of thousands of pounds. It is rightly one of Oxford's treasures.

"Yet there on our canal, in our city, is the living equivalent - the water, the sunlight, the trees, the people at work, the passers-by, the boats, the church with its tower.

"Are we so careless of what our city possesses that we're willing to guard the painting so diligently, and yet let the reality be wiped out with one stroke of the planner's pen?"

The author conceded that the city needed new houses and flats but "not this sort of building on this sort of site".

He urged the inspector to turn down the application and preserve the site for the boatyard and "for a genuinely human-scale housing development".

The area around the boatyard was one of few remaining parts of the canal that had not been blighted with buildings that were too big, Mr Pullman concluded.

Jeremy Cahill, the barrister acting for Spring Residential, asked the writer why a pull-out map in his book Lyra's Oxford showed a coal wharf in front of St Barnabas' Church, not a boatyard.

Mr Pullman replied that the map was part of a work of fiction and depicted an imaginary Oxford landscape.

Jenny Mann, of Jericho Community Association, told the inquiry the development would have a "highly negative impact on the historic setting of the canal and church, on the daily lives of those who live closest to it, and on the infrastructure of our community".

The development firm has argued it should be allowed to build the flats, despite offering only 35 per cent affordable housing, not the 50 per cent minimum set by the council. The inquiry concludes next week.