Hi, I'm in the UK too! Welcome.
My thoughts on your situation and budget are thus:
Petrol #1 £40 / month
Petrol #2 £50 / month
How are you only spending £90 a month on petrol with those commutes? Not that they are especially long, but petrol ain't cheap. I wonder if some of your unaccounted for money is going on this? It's easy to say, oh I only fill up once a month, but really, do you? Or do you go and visit the in-laws and fill up and think, oh it's a one off, but really it's every six weeks, on top of your usual fill up?
Can you save on your insurances by paying yearly? I never pay monthly because it is almost always more expensive (I'm hoping you just broke down the cost for the sake of budget clarity). Even our life insurance is about £9 a year cheaper because we pay annually, although this is an option I had to specifically request.
Personally, I am focussing on paying off our mortgage, because rates aren't fixed for the whole term as they are in the US (one major difference you will notice, and the reason so many here are anti-paying off mortgages). I remember my parent's rates going up to 15% in the 90s.
I currently have a 2 year deal at 2.49%. There is no way I'm going to be able to continue that rate into the future. I'm aiming to pay it all off before the end of the term. Yes, mortgage borrowing is cheap borrowing, but the length of time you borrow for makes it expensive (compound interest works both ways, you know?).
But I know a lot of people think you are better to invest the money. For me, personally, the peace of mind is worth it, and since I can get it done in 2 years (only because I've joined MMM and now save 50% of my income! In 2009 I was in major debt, btw, so it totally can be done) I will start aggressively investing in 2 years, when I own my home outright.
Also wanted to reiterate that your broadband seems high. We need some super-duper VPN connection or something for my husbands work, and we 'only' pay £25 for a ridiculously high level of service.
Finally, don't fall into the 'Christmas needs paying for' trap. It doesn't need paying for. You make it sound like a passive thing - it's going to happen to you, and you just have to foot the bill. That is not true, nor is it the MMM way. Christmas costs however much you spend.
Hope I've not been too harsh. Love seeing other Brits here!