Will anyone believe that though? Given the propensity of virtually all governments worldwide to do less than promised and the overwhelming amount of infrastructure still needed, I don't take this date seriously at all.
Before 2020: https://ec.europa.eu/clima/policies/transport/vehicles/cars_...
From 2020 onwards: https://ec.europa.eu/clima/policies/transport/vehicles/regul...
On paper. In reality [0][1] unless you drive all electric all or most of the time the actual, real life CO2 emissions are far worse. Because now you have an ICE engine that hauls around an extra battery and electric motor, occasionally inefficiently charging the battery by burning gasoline.
Many (most?) PHEVs owners don't have charging at home (reason to buy hybrid), and the rest of the charging infrastructure is far more inconvenient to use than a gas station. Depending on where you live it may also prove more expensive to drive electric. Add to this the small battery and you see why most of them are driven mostly in ICE mode.
This being said, if I were in the market for a new car I really wouldn't care about what the government promises will happen in 2030. I'd look around to see what makes sense for me. Is the government doing anything about it? Are they heavily investing in making this a reality (new chargers, new electrical infrastructure, etc.)? Talk is cheap.
[0] https://theicct.org/publications/phev-real-world-usage-sept2...
[1] https://www.telegraph.co.uk/news/2020/02/05/revealed-plug-in...
But yes, UK company tax structure around them is absolutely broken. You can get one, get a massive tax discount, and then simply never charge it, resulting in higher emissions than in a normal car, and yet keep the low emissions discount. It's stupid. I think you should have to prove that you're actually using the EV capabilities, otherwise it's just straight up fraud.
The ability to charge will drive infrastructure investments from the bottom up. Especially if it's cheaper than fossil fuels. My guess is we will start to see charging mentioned as a selling point in real estate ads in the coming years. Same with charging at stores or similar, although that is more limited.
All while helping BEVs become even more attractive.
And that's the crux of the matter, most people buy hybrids because they can't charge at home. Those cars end up driving a lot on gas. If you can't conveniently charge at home or at work, waiting for 1.5-2h to charge for 40-50Km is far less appealing than 3 minutes for 500Km worth of gas. Place more chargers and make gas more expensive than electricity and the situation would probably change.
One specific German manufacturer featured in the studies I linked above sees most of the kilometers driven in their hybrids using the ICE, with a lot of that time the ICE inefficiently charging the battery, and almost cancelling out the fuel efficiency brought by the electrification. The number of people who see anything close to the officially estimated fuel consumption or CO2 emissions is vanishingly low. And the manufacturer knows it but they aren't ready with EVs, they have to meet new fleet regulations, and they wanted to benefit from the incentives the German government offers to manufacturers for any EV or PHEV.
Looking at a family member in this situation (the one who provided me with the statistics from the manufacturer), they drove ~2000Km in a brand new PHEV with ~11 liters + 9KWh per 100Km. The manufacturer suggests ~2 liters per 100Km. That's where most efficiency numbers revolve for that particular PHEV. It doesn't help that where they live in Germany charging the battery at a public charger even when assuming the full ~40Km range is 30% more expensive per Km than filling the tank but this is a local issue that's not generally applicable.
