Naturists run the risk of being criminalised under proposals in the Sexual Offences Bill, it has been claimed.
Naturists fear the sex offences legislation
Mick Ayers, the chairman of the central council of British naturism, said parts of the Sexual Offences Bill aimed at streakers could also cover naturists.
Mr Ayers sought to draw a distinction between the way naturists exposed themselves and that of sex offenders.
"People who expose themselves for sexual gratification tend to be obvious - and if you are a male person it's very obvious in certain cases," he told the home affairs select committee.
Dressed in a suit and tie, Mr Ayers, from Lowestoft, Suffolk, urged that the Bill be altered to draw that distinction and target only those exposing themselves for sexual purposes.
"We prefer not to be caught in friendly fire, as it were," he said.
"If you are on a naturist beach it should be a defence that a reasonable person should expect to see naked people."
Mr Ayers went on to outline how the 20,000 members in his organisation were granted a "naturists passport" which could be confiscated if it was thought their motivation for joining appeared questionable.
"If they believe naturism offers them something of a sexual activity and contact, they are very quickly disillusioned and leave," he said.
Also giving evidence to the influential Commons committee were the chairman of the Criminal Bar Association, Peter Rook QC, Jan Berry who chairs the Police Federation and Cathy Halloran of the Rape Crisis Federation.
After giving evidence Mr Ayers said that about 2.5m people in the UK practised naturism.
The Bill proposes tightening the law on exposure although such activity can currently be dealt with under existing public order and decency laws.