Snow on the way!

The nice AA website also included this, so be aware:
Over the winter of 2010/11 we did hear reports of some insurers increasing premiums or remarkably even refusing cover if winter tyres are fitted. As a result we recommend talking to your insurer if you are considering fitting winter tyres.

Now there's a turn-up for the books! I wonder why that was?

Any excuse? or a valid reason?

I googled and it seemed to have been something to do with winter tyres not being suitable for the roads if the temperature is above 7 degrees.

Here's something more up-to-date, which seems that they are fine with it, only one or two require the insured to let them know:
www.abi.org.uk/~/media/Files/Documents/Publications/Public/Migrated/Motor/ABI%20guide%20to%20winter%20tyres%20The%20motor%20insurance%20commitment.pdf