Hi,
I applied years ago to a company that Diabetes UK put me in touch with (the charity, not this site), but they excluded anything related to diabetes & had a higher premium, so I didn't take it out.
I have just been accepted for income protection with a company called Cirencester Friendly - they were the only company that would consider covering type 1 diabetics I think - I know my financial adviser rang every company he had in the phone book. They also exclude any pre-existing conditions, but the premium is unchanged. They will only consider you if your HbA1c is under 7.5% though.
Good luck!