I wouldn't take the fact that it is only 10e higher for a whole of life policy into account too much. Premiums will nearly always be lower when you are younger (unless there are health/occupational issues etc). Whole of life policies will be reviewed and premiums increased during the life of the policy (as you age).
The main benefit (in my opinion) of whole of life policies over mortgage protection policies is that they are more flexible ie if you trade up the sum assured can be increased and often additional benefits can be added on to them if you are eligible such as critical illness, hospital cover etc if they are not covered by your private health insurance (all of which will increase the premium).
Peoples life assurance requirements differ depending on their circumstances such as dependents etc. If you require additional cover taking out another policy separately from the mortgage protection will at least ensure that the mortgage is paid off and there are additional funds available to dependents should they be needed. This can be achieved with a whole of life policy but you may end up paying a higher premium unnecessarily in the meantime depending on your circumstances. If you are taking out cover solely as a mortgage requirement the basic mortgage protection policy should be enough.