Norway is officially the first country in the world where most car sales are electric vehicles.

58 percent of all new autos registered in March were EVs.

Greens say that's a boon for the environment, and shows how popular such cars can be.

Skeptics say it's all down to generous state subsidies.

EVs largely avoid the taxes and tolls applied to regular vehicles.

At this Tesla dealership one buyer says money is indeed the main concern: (SOUNDBITE) (English) TESLA BUYER MAQSOOD AHMED, 35, SAYING: "For the time being I think you're paying once for the electric car and then it's like free, you don't have to pay another thing.

So, I think that's the advantage.

People are trying actually to save money here." Norway has accumulated vast wealth thanks to its oil revenues.

It's used that money to help encourage the shift away from traditional engines.

The country's electric vehicle association says it's about putting a price on fossil fuels, and the critics are wrong to talk about subsidies: (SOUNDBITE)(English) SECRETARY GENERAL OF THE NORWEGIAN ELECTRIC VEHICLE ASSOCIATION, CHRISTINA BU, SAYING: "And I've named this argument "Norway is rich argument" because it's not actually how it works.

What we do is taxing cars heavily and that money is used to promote the low emission or zero emission cars." For the whole of 2018, EVs accounted for just under a third of all car sales in Norway.

That's far ahead of any other nation.

The debut of Tesla's relatively affordable Model 3 sedan helped spur the latest jump.

Now the 50 percent mark might just be the start: (SOUNDBITE)(English) SECRETARY GENERAL OF THE NORWEGIAN ELECTRIC VEHICLE ASSOCIATION, CHRISTINA BU, SAYING: "Well it's hard to see what the future brings but in my opinion we will reach the hundred percent market share in 2025 without doubt."