Ah, now why didn't anyone tell me about the maternity band. A lovely stretchy wide piece of comfort to go under, or over, pretty much any item of clothing. Fits just nicely over the bump and below.
Since I am determined to keep wearing a pair of my favourite jeans I today bought a great pack of 3 (grey, blk, white) from New Look for a mere £10. Bargain considering the options they have made possible. A host of tops become feasible again. Fabulous.