Good comment James,
I would be keen to find the answer to this question also, if anyone could help please make a post. I am sure HSBC can't be the only bank prepared to assist in this situation. There are people who use a multitude of credit cards for frivolous spending and end up being in excess of £50k's worth of debt, so I can't believe the banks can be so restrictive with their terms.
You have very helpful parents I must say.