The resident population in Switzerland is expected to increase to nine million from 7.8 million over the next five decades, according to a study by the Federal Statistics Office.
The Statistics Office said the rise would be mainly thanks to immigration.
The proportion of people over aged 65 or more, which is now about 17 per cent, is likely to increase rapidly to more than 28 per cent.
Experts say the demographic trends will largely determine the evolution of the working population, which is expected to decline to 4.6 million by 2060.
At the same time, the educational level of the population of Switzerland will grow.
The scenario lends weight to political moves to increase the retirement age from 65 for men and 64 for women.
swissinfo.ch and agencies
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