Sainsbury's also completed a property review of its pipeline and identified 15 to 20 edge-of-town sites where it no longer wants to build a supermarket. As a result it will suffer a one-off £92m impairment charge. Chief financial director John Rogers said: "These are mostly edge of town sites where the town centre first planning policy is now redundant so it is no longer economically viable for us to open a supermarket." Sainsbury's has also set aside £13m as a provision for a commercial item, which it said "for which we intend to defend our position". Rogers said this cost is not allocated to the ASA decision on Tesco's price mechanic which it is taking to judicial review, but rather it is "a separate matter where we need to defend our position". Sainsbury's launched its Christmas ad campaign this week, featuring clips from film director Kevin Macdonald's Christmas in a Day documentary.