Not sure it has anything to do with Brexit, but for those thinking of retiring to the UK, this 'news' story might be useful :

https://thewest.com.au/business/your...ng-b881045685z

The article doesn't expressly say it, but Class 2 contributions only apply to self-employed people. When I worked in the UK my employer paid Class 1 N.I., and if I wanted to fill in gaps in my record that's the rate I would have to pay (as Class 3 AVCs). Currently Class 3 costs £14.65 and Class 2 £2.95 pw for the current year.

Like you say, nothing to do with the B word!