Budget is flexible but id say £700 absolute maximum.
At £700, you might be best suited by attaching a kit to a suitable bike you already own or one you can purchase cheaply. (not difficult)
Second-hand can be a good option and there may be some available from the big dealers or the classifieds on this site.
The most important thing though is to take a day out and visit one or two places with EAPC stockists. Bristol might be a good starting point in your case? That way, you can get a feel for a bike on a test ride and buying something that is (1) comfortable for you and (2) capable of providing enough assistance to your pedalling over the kind of terrain you will be riding.
On a limited budget, it really is important to try and get it right first time. What you don't need is to blow your budget only to find within weeks that your choice doesn't quite do what you want it to do and then you start thinking about laying out more money on something better.
A lot of people make the mistake of buying a bike completely unsuited to the kind of riding they will mostly do. For example, (although you state it would be for leisure use), will you want weather protection? Will you want to carry goods, shopping or anything else? These issues are not to be sniffed at as if you don't have mudguards and a rear carrier, you may need to spend more of your hard-earned if you buy a 'naked' bicycle then decide you want to use it whatever the weather. Moreover, good rainproof clothing don't come cheap.
While there are always some apparent bargains at the budget end of the market, those machines may not necessarily be well-built or reliable. That reliability, (or lack of), may stretch to the seller too and it's worth mentioning the old adage, 'You buy cheap; you buy twice!'
Also worth mentioning is the fact that for not a great deal more than your stated maximum budget, there are companies selling EAPCs whose owners contribute to these pages with models to suit most needs. These sellers are noted for their after-sales service and warranty provisions as well as keen prices, so you may wish to further examine your options for the sake of getting the right bike first time with the reassurance of a good guarantee from a seller, highly regarded by most users of this forum.
To that end, though you may already be aware, I would point you in the direction of Cyclezee, Kudos, Whoosh and Juicy. There are others but these four all supply pretty solid machines at a variety of price points.
Best of luck!
Tom
