Liberal Britain may have reached its peak, with the proportion of people who say they are completely comfortable with same-sex relations having fallen for the first time in more than three decades.

Research conducted as part of the British Social Attitudes (BSA) survey signalled the country had “reached a point of plateau”, where acceptance of those not fitting within “conventional norms” is beginning to level off.

Of the nearly 3,000 people polled, two-thirds (66 per cent) said same-sex relationships were “not wrong at all”, down from 68 per cent the previous year – marking the first drop since 1987, when the figure stood at 11 per cent.