With Britain baked in record high temperatures this week and plenty more sun predicted for the summer, motorists might be thinking now's the time to buy a convertible car... but they'll struggle to find one in showrooms.

That's because top-down cars are rapidly accelerating towards extinction.

The number of new convertible models on sale in the UK has slipped to a 20-year low, with just 11 soft-top cars available from the 30 most popular brands.

In the last 12 months, the number of available roadsters and cabriolets has plunged by 31 per cent, according to market analysis by used car website CarGurus.

Despite Britain’s comparatively mild climate, we are historically one of Europe’s biggest markets for cars with retractable tops.