Applicable discount rate for coupon paying bond

Hi,

I have a small question on pricing a coupon paying bond.

Let say, I have a coupon paying bond issued by a top rated Govt bank
in UK. Coupon is payable semi-annually. To price the bond what
discount rate should be applied for each future coupon and principal
payment?

Should I use term structure of LIBOR? or LIBID? Or average of both? Or
something else?

Any pointer will be appreciated.

Thanks,