Advertisement betrays a noticeable lack of diversity.

A billboard has appeared in London encouraging white people to sterilize themselves to solve overpopulation.

The sign, which was put up on Holloway Road, says "Imagine a city less crowded… do your part–get sterilised! Yay!"

The advertisement betrays a noticeable lack of 'diversity' as it only features caricatures of white people and no people of color.

Another Twitter user responded to the image by noting that a similar billboard had been erected in his home country of Portugal.