Try looking on Answerbank or just do a google search on "key issues facing Barclays Bank'. This question is asked at least once a month on AB and regularly on other sites too.
I'm surprised Barclays haven't changed this question now as they seem to ask it to all job applicants and loads of answers are available on the web.
Anyway, I think the issues surrounding the banks (take overs, collapses, financial difficulties), the credit crunch, the recession etc, are well documented so even if you have been asleep for the last 12 months you'll be able to find loads of info from a quick web search .