Sir – In the last couple of weeks we have seen councillor Hollingsworth on television, and councillor Hayes in your pages patting themselves on the back because, they say, by approving the Westgate extension, the city has “created” 3,400 new jobs.

Wonderful! But how many jobs will approving the extension destroy? When major new shops are added to a market-place, older shops may lose customers and some may be forced to close.

When the Westgate extension was first mooted, the city council examined what its effect on other shops would be.

The city estimated that the extension would reduce trade in other city centre shops, the district centres such as Summertown and towns in the catchment area such as Witney and Thame, by 10-15 per cent.

This may imply that up to one in six shops may fail once the extension is fully launched. But the city council decided this was too little to justify rejecting the application.

At the inquiry in 2001 the developers expected that by 2008, when the Westgate extension would be fully launched, more than 40 per cent of their turnover would be diverted from existing shops. But they forecast that prosperity in Oxford would be so high by 2008, those shops wouldn’t notice the loss.

How many jobs will the extension destroy? There are about 10,000 retail and wholesale workers in Oxford, and perhaps a similar number in the towns and villages in the catchment area. 10-15 per cent of this number could be 2,000-3,000 employees put out of work.

But the forecasts above were made for a proposed £200m extension with 1,300 employees. We are now to have a £500m extension employing 3,400.

The number of jobs that will be destroyed could well outweigh the number “created”.

M. Treisman, Oxford