This week Channel 4 will begin a new series of Shameless, the series set around the Gallaghers, described by the producers as “the UK’s most dysfunctional family”, on the fictional Chatsworth Estate.

The father figure, Frank Gallagher, is an ageing “Neet” — the government’s own acronym for those of working age who are not in employment, education or training. The surprise, and this is perhaps why the series is fictional, is that his children are hard working although they are mostly still at school. In real life they would almost certainly end up as Neets.

If so they would join more than a million others. The number of young people aged 16 to 24 in Britain who are classified as Neets stands at 1.24m. The number of young male Neets has risen by 27% to 575,000 since the spring of 1997, while the number of young female Neets is also up but by only 6% to 669,000.

Other countries have Neets although only in Britain, and curiously Japan, is the problem considered significant enough for the term to be widely used.

The Neets are the yobs hanging around off-licences late into the night. They are the graffiti artists who cannot spell and the drug-dealing pit-bull owners. They are also the Vicky Pollard types who become single mothers. Not all Neets fit the caricature. A young mother in a stable relationship bringing up children at home would be classified as a Neet. So could somebody temporarily out of work, such as a university graduate looking for their first job.

In many cases, however, Neets do fit the caricature and are responsible for much more than their fair share of crime and antisocial behaviour.

A study by the Department for Education and Skills in 2005 found that the proportion of Neets among 16 to 18-year-olds “has remained stubbornly persistent” over the past decade at about 10%.

Research assembled by Reform, the think tank, shows that on the government’s own figures, each new entrant to the Neet class will cost the public £97,000 over their lifetime, with the worst examples weighing in at more than £300,000.

The same study also analysed their social impact. Drug use among 16 to 18-year-olds is higher, with 71% admitting to having used illegal drugs, compared with 45% of non-Neets. This and other factors had an impact on their health: 15% of male and 25% of female Neets were in poor health by age 21 (compared with 10% and 15% respectively of non-Neets).

Neets are also more likely to have children earlier — potentially disrupting their education. Some 60% of Neet women have had children by the age of 21, compared with only 10% of the non-Neet population. They are also more likely to drift into crime.

The same study found that 29% of male and 8% of female young Neets were involved in crime, three times the rate among all young people. It estimated that the cost to society of the Neet class in terms of crime, public health and antisocial behaviour was so high that a single 157,000-strong cohort of 16 to 18-year-old Neets would cost the country £15 billion by the time they died (prematurely) in about 2060.

David Willetts, the Tory shadow education secretary, says the problem is down to educational failings. Neets tend to do badly at primary school, leaving without being able to read or write properly, and then getting stuck in the slow lane at secondary school. Children who have neither parent working, like the Gallaghers, or a single parent who does not work, are much more likely to end up as Neets.

The rising number of Neets also reflects another government failing. When he introduced the “New Deal” for young people in 1998, Gordon Brown insisted that there would be “no fifth option” beyond work, training, education or starting a business. But the New Deal, for many, has proved to be a revolving door back to unemployment. And the Neets have discovered that there is indeed a fifth option. Most continue to claim benefit while happily ignoring the strictures of our future prime minister.

“The New Deal is very effective, by international standards, at what it does — getting young long-term unemployed benefit claimants into jobs — but its focus on unemployed benefit claimants has meant less was provided to the majority of 18-24 Neets,” says Paul Bivand, head of analysis at Inclusion, a non-profit organisation which promotes social justice.

The Neets are part of a wider problem identified by Nicholas Boys Smith, a welfare expert. Welfare, he says, has become the forgotten problem, largely because of government propaganda which implies that the benefits bill is now trivial and that most spending goes on health and education.

In fact, as he points out, spending on social security in 2005-6 was £79 billion, excluding pensions, £6 billion more than was spent on education and not that far below the health budget of £96 billion.

The number of working age people dependent on benefits, 5.4m, or 14% of the age group, has stayed high, as has the tendency for them to be benefit “lifers”. More than 70% of claimants remain on benefits for over a year.

For the Neets, and for others on the margins of the workforce, there is a particular problem now that was barely on the radar screen when Brown was talking so bullishly about his New Deal in 1998 — immigration.

In a speech last week David Blanchflower, one of the members of the Bank of England’s monetary policy committee, said it was wrong to blame immigration for the rise in unemployment over the past year or so; it would probably have occurred anyway. The government’s own research has come to similar conclusions.

However, there is no doubt that the arrival of skilled and enthusiastic immigrants from eastern Europe has raised the bar for Neets. Those willing to work face tougher competition than their predecessors.

In many cases they offer no competition. Sir Digby Jones, appointed as the government’s skills “czar” last month, gives the example of a Scottish employer who offered jobs to unemployed young people. On the first day some of them did not turn up; by the end of the week none did. The Polish workers he employed instead, in contrast, have yet to take a day off.

The Neets are going to be with us for a very long time.