Machine Mart have a cheap drill powered pump (use cordless on the plot) suitable for transferring water to your butt if hoses are not allowed. Would also be OK for filling water butts from the bath for those of us with downstairs bathrooms.
http://www.machinemart.co.uk/product.asp?p=060220450&r=2165&g=122
A better one, this time from the Draper range, as it has adapters for 1/2" hose (standard hosepipe) and is a bit cheaper - you may be able to get it delivered to your friendly Draper stockist
http://www.draper.co.uk/Pages/Pagesource/p405.pdf