Against my better judgment, I decided to use a comparison website. Specifically, Compare the market.
The data capture form asked for my phone number ( with a rider that it was for admin use and I would not be bothered by sales calls... or words to that effect.)
The website hadn't even finished disgorging the quotes before the phone started ringing
As of now, I have had a total of 86 phone calls.
That's the first and last time I'll be doing that. Especially as you can easily get cheaper and better quotes by going to each firm direct.
Apparently, in accepting the terms and conditions of the comparison website, I allow each of the insurance firms to pass my phone number on to "specially selected trading partners" as well