In the long run everyone's insurance premiums go up. They wont reduce male drivers premiums because they "can't" so they will increase female ones.

This ruling is terrible, I have been benefiting from having my girlfriend on my insurance for 10 years.

Why "can't" they? .. Happy to be proven wrong: http://news.ycombinator.com/item?id=2298570

That is why I put it in quotes. They "can but wont" which translates to "We can't because insurance for men costs more because of the statistics". Given that rule of thumb they will increase females premiums.

Not only have I worked for insurance companies, but if I was one, this is exactly what I would do if I was told everyone had to be treated equally.

How do you figure? It's unlikely insurance companies will reduce their premiums for male drivers, they'll just increase the premiums for female customers.

Let me try and explain my maths, previously the fee where £100/£50 (M/F) income of £150. So they will have to increase F fee, so it will be (£100/£100) income of £200. Due to competition someone will then lower their fee to be (£75/£75) back again to £150 income.

So in the long run, my statement stands, it will cost me less.

I think you are seriously over-estimating the level of true competition in the UK Car Insurance Market. (hint; there are almost certainly less actual distinct insurance providers than you think...)

Yer, Just a few: http://www.gocompare.com/insurance-companies/

Their may have the same under-writers who set the same rates for every broker. Its the brokers were the competition is.

That is why I put it in quotes. They "can but wont" which translates to "We can't because insurance for men costs more because of the statistics [showing men have more claims therefore have to pay higher premiums]". Given that rule of thumb they will increase females premiums to make them equal.

Not only have I worked for insurance companies, but if I ran one, this is exactly what I would do if I was told everyone had to be treated equally. How can I charge men less if I know that they are going to make more claims?