I agree with the OP that the price of soft drinks in UK pubs is a rip-off. A pint of beer bears duty (tax) of around 37p (I think - it went up 1p a pint today, in the budget), so if a pub charges the same for beer as for lemonade or coke, they are making that amount extra per pint in profit, on the pop. [pop = fizzy soft drink such as lemonade or coke, for the benefit of US readers!]

When I were a lad, and a bit skint, I used to drink shandy because it was cheaper than beer. These days, it can often be more expensive (I don't like shandy these days anyway, as I find it too sweet - but that's another story). This was explained to me by a licensee as the cost of serving it - it takes longer to pour a pint of shandy than a pint of beer, and of course time is money.

I'm not sure what can be done about it, because if people are prepared to pay these rip-off prices, they will continue.

I won't drink soft drinks in pubs anyway, because I don't like them except in small quantities. I could never drink pints of coke or pop, and just limit myself to less beer if I'm driving. If that means making a pint last a couple of hours, then that's what I have to do (of course I'd rather drink more beer, but...!)

In any case, as far as the responsible drinking is concerned, I'd like to see the drinks manufacturers make greater efforts to produce low alcohol beers that actually taste like beer. It's possible to make a pint of ale with less than 2% alcohol, and still tastes fairly drinkable, but these are very few and far between. Most of the low alcohol or alcohol free 'beers' on the market taste disgusting and are no substitute. Then beer drinkers would have a more viable alternative to drink, instead of the bloatmungous fizzy sweet concoctions on sale in most boozers.