Probably pre war as no black out masks,first row C3911361,C3911279,PMF 572,PME 893,PMF 239,PMF 257,two bikes in right back ground are PMF 244,and I think PML 28. 
Steve, that's great. I've never seen a view from this side before so never been able to link census serials to registration numbers.
The elderly officer is The Duke of Connaught. He died in 1942. The News Agency Caption is dated 20/8/1939 - Connaught was apparently Colonel in Chief of the Corps of Military Police.
