Justice Secretary Chris Grayling is said to be planning a “crackdown” on sex in prisons, which would involve preventing prisoners in relationships from sharing jail cells.

At the moment there is no data on how many inmates are in same-sex relationships but the prison authorities accept there is a “degree of inevitability” to sex occurring in jails.

According to the Telegraph, one source close to Mr Grayling said: “We don’t want and we will not accept prisoners replicating cosy, domestic relationships by being able to share cells in our prisons.”

The Howard League is currently conducting the first ever inquiry on the matter, which will look at relationships that are not simply physical.

Sex in prison is not allowed under current laws although charities believe it is relatively common.

Under current guidelines, prisons make condoms available to inmates under prescription from a doctor.

Andrew Neilson, director of campaigns at the Howard League for Penal Reform, said it should be remembered that “people in prison are human beings.

“It’s inevitable that as soon as you put people in a closed environment for a sustained period, human nature takes its course,” he added:

“Chris Grayling should take care before putting time and money into an unenforceable puritanical crackdown. He will find human nature a powerful and costly adversary.”