SEX education should be compulsory in schools to teach children about the dangers of predators and 'sexting', a Southampton professor told MPs.

Roger Ingham, director of the Centre for Sexual Health Research at the University of Southampton, warned current lessons - which are voluntary - are “incredibly patchy”.

And he called on the Government to end that postcode lottery by ensuring “such an important issue” is taught properly, by properly trained teachers.

The professor said: “Young people are facing huge pressures - and those pressures change, as new technology comes in. They need the skills and ability to cope.

“Sexting has come in and everyone is panicking about it - it's great threat. And the same about abuse, or what people are saying to them online.”

Professor Ingham, giving evidence to the education select committee, also launched a fierce attack on pressure groups - and newspapers - which scare parents about what such lessons involve.

Protests by the Society for the Protection of Unborn Children (SPUC), about leaflets on puberty that had simply contained pictures of body parts, correctly described as 'penis' and 'vagina', had sparked tabloid stories.

Professor Ingham said: “It's not surprising, if parents see that, that they get nervous about sex education in primary schools.

“When they are told about why it's better to use the correct names - rather than silly, made-up names - they fully understand the point.”

The professor was giving evidence to an inquiry into whether Personal, Social, Health and Economic education (PSHE) - including Sex and Relationships Education (SRE) - should be statutory in schools.

Watchdog Ofsted has raised the alarm over poor sex education in one in three schools, leaving pupils vulnerable to sexual exploitation and pressures from online pornography.

Meanwhile, independent 'free schools' and academies are allowed to drop even these half-hearted attempts at lessons - and many have.

Professor Ingham helped put together a 2008 report calling for compulsory sex education, which was defeated in the Lords on the “strange” argument that it “doesn't work”, he said.

He added: “It's such an important issue. Unless we make it statutory, we won't get the shift in attitudes among school governors, teachers and parents that we need, to give this more serious consideration.”

Arguing pupils needed a right to challenge, when they were missing out, Professor Ingham said: “It's left to individual schools and it's incredibly patchy.”

However, last year, the Government defeated a Labour amendment to the Children and Families Bill which attempted to make sex and relationships education compulsory.