This is a late 1950's/early 1960's Ben Zuckerman suit in pale blue/lilac houndstooth wool. It is a classic design with a knee length skirt and a jacket with a slightly nipped in waist.
I also have an outfit made from the identical material, also by Ben Zuckerman, consisting of a coat and dress, which can be seen here. Ben Zuckerman would often use a high quality material for a number of outfits in one season.
Photos courtesy of Vintage Martini.