Councils in England have vetoed one in five recent office-to-residential applications, new research has revealed.

Property consultancy Daniel Watney’s analysis of government data found that between April 2014 and June 2015, 916 of 4,887 applications for conversion through permitted development rights (PDR) were refused on ‘prior approval’ grounds across England.

This was higher in London, where one in four - 493 of 1,959 applications - were blocked. The average for other cities was one in 10.

The research is the first national overview of office-to-resi applications since planning laws were relaxed in May 2013.

PDR allow office-to-residential conversions to be carried out without a planning application. However, developers still have to seek prior approval from councils where certain other planning consents, such as transport and highways issues, contaminaiton and flooding risk, are required.

Charles Mills, partner at Daniel Watney, warned that councils should not misuse the prior approval process as a “workaround” to veto conversions.

The research found that Bristol has approved the most conversions at 54, while Brighton and Hove has rejected the most - turning down 12.

In London, Richmond upon Thames, in the south west of the capital, has had the greatest number of applications at 208, refusing 74 and approving 134.