Online retailers who sell age-restricted products to children should be jailed, according to one MP.

Margaret Moran, Labour MP for Luton South, said internet retailers are not doing enough to stop children going online to buy items they would be refused in shops.

To combat this she has introduced a bill to Parliament to force retailers to take responsibility for illegal sales.

"Sadly, self-regulation is not working," said Moran. "I believe that online retailers selling alcohol, knives or pornography to under-age children should face a hefty fine or even imprisonment if they fail to put in place procedures to check the age of their customers."

However, there are real problems in verifying a child's real age for online retailers; some children use their parents' credit or debit cards with or without permission. People are also increasingly using pre-pay cards.

James Roper, chief executive of the IMRG, the e-retail industry body, said: "It is an impossible situation. Yes, it is something we need and we want to do. But without an ID system, and we are nowhere near having that thanks to the arguments and incompetence surrounding the issue, we are not going to be able to stop these children."

However, Moran pointed out that the gambling industry was having to take technical measures to ensure online gamblers were over 18, and online retailers should do the same.

"We cannot have a wild west scenario whereby anything is sold to anyone and no-one takes responsibility," she said.

The Online Purchasing of Goods and Services (Age Verification) Bill had its first reading in Parliament at the end of last month. The Bill would require online retailers to take positive steps to ensure age compliance.

The Bill will have its second reading to the House of Commons on 16 May, at which point it will be generally debated. Most Private Members' Bills do not become law but can succeed in raising awareness of an issue.