SIR David Attenborough and the Optimum Population Trust (OPT) are, of course, entirely correct in arguing the virtue and necessity of reducing the world’s human population.

They are, however, quite wrong to pursue this through their Stop at Two campaign, which shows complete disregard for the extreme selectivity with which the message will be received.

Their influence extends no further than the small section of mankind whose fertility rate is already substantially below two.

They are, in effect, saying to us “please fade away even faster so the others can go on having six children per couple for a bit longer”.

An Englishman would contribute more effectively to demographic stabilisation, or reduction, through having two children by an English wife, two more children by an African wife and another two by his Asian wife.

In so doing, he could forestall the several additional children who would be born if these extra wives were left to fall under the tutelage of husbands who are unmoved by the OPT’s concerns.

John Riseley, Harrogate, North Yorkshire.