Petrol may be the "most appealing" when you look at on vehicle cost alone, when if you consider the cost of maintenance/fuel as well, then the EV is likely to be cheaper over all. Not only would its tax be zero (petrol anything from £20 to £400), but the cost to recharge its batterly would be as low as £3.50 (50kW @ 7p kWh when charge at night on economy 7 rates) vs refueling a petrol/diesel tank for £62/£65. So if you refueled twice a month, your already nipping at the door of an EV in terms of cost of ownership. More than twice a month and the EV becomes an absolute bargain. When you add on general maintenance as well then the costs really start to spiral.
If I were in a position to buy a new car now, I wouldn't think twice about it, i'd get an electric car regardless and I live in a flat, the infrastructure is there for charging if needed in an emergency but a cable out the window would suffice for the time being.