I will be cruising to Southampton on QM2 and would like to place a suitcase in storage at train or bus station. Or London. Any ideas ?

I do not believe there are any storage lockers at bus or rail stations due to terroist threats and actions.

I checked Waterloo station and found the following for checked luggage:

Left Luggage Monday-Sunday 07:00-23:00

Left Luggage - Note £6.50 per item per 24 hours. Located on platform 11

I expect the same would be true of all the main line rail stations--Paddington, King's Cross, St. Pancras, Victoria, etc. Most terminals at the major airports have Left Luggage. Don't know about bus stations but the major Victoria bus station is linked to Victoria rail.

Make that terrorist. Also, don't know about Southampton but Cunard/QM2 info line could advise.

There are plenty of left luggage facilites in London, majority of them at train stations. Not cheap though.
http://www.left-baggage.co.uk/locations.php

Thank you YK that was most helpful. Now I can guage how much it will cost me. Much Abliged. CIAO!