One in four teenagers thinks it is acceptable to cheat in exams, new research found.

And many see no harm in shoplifting or fare dodging on public transport.

The report raises concerns that many students will start adulthood believing that unethical behaviour is acceptable.

It concludes that the findings are "clear evidence" that youngsters should be given ethics lessons as part of the curriculum.

The report, which questioned 10,000 13 to 15-year-olds between 2008 and 2010, found that a quarter believe it is fine to cheat in an exam.

Girls are less likely to cheat than boys, it says, with children from working class families more likely to condone cheating than those from professional backgrounds.

Just over one in five (22%) see nothing wrong with travelling on public transport without a ticket, with older students more likely to dodge a fare than younger pupils. And nearly one in 10 (9%) said they think shoplifting is acceptable. This is a 29% increase from 10 years ago, when a similar survey was conducted.

However, the poll did find that many teenagers have a strong work ethic and sense of social responsibility. Nine out of 10 said they believe a good work ethic is important in the workplace and about half said they would like to do a job that helps other people.

In total, 80% of teenagers said they believe they can do something to help the world's problems, compared with 75% who said the same a decade ago.

The survey was commissioned by the Money & Morals schools programme to mark the launch of the moneyandmorals.org website.