Sorry for being so delayed in responding, I've been a away.
nicolas wrote: It has to be one of the points listed here:
www.hikashop.com/en/support/documentatio...ins-listing.html#faq
If you can't find it, please post a screenshot of the paypal payment method options.
Sadly it was none of the points suggested in your links though it was appreciated as a check list. Once those points had been discounted I looked elsewhere. While checking the shipping options in the PayPal options I noted that the only option on offer was one that wasn't even published. The one I wished to use didn't appear though it had a very similar name. I uninstalled the unpublished plugin which caused the frontend of the site to crash and Hikashop admin to fail completely leaving a long list of "Path not found" errors. I restored the Hikashop Components and reinstalled the shipping plugin. This appears to have resolved all the problems.