A £2bn scheme to improve basic skills among adults has been called a "depressing failure" by education inspectors.
The Skills for Life programme is not working, inspectors say
The Skills for Life programme aims to boost literacy and numeracy skills.
But the Adult Learning Inspectorate said the initiative was not working, despite the "extraordinary" amount of money the government had spent on it.
The report was particularly critical of skills programmes in prisons, with over half offering "inadequate" provision.
The report said "too many" managers in prisons were failing to correct faults and weaknesses pointed out by inspectors.
And there needed to be greater awareness among all prison staff of the role they played in developing skills.
The inspectors said Skills for Life was not achieving its key aim of helping people from the most disadvantaged backgrounds.
"There has been a depressing lack of improvement and a failure effectively to tackle weaknesses over the past four years," its annual report said.
"This is despite an extraordinary injection of funds and capacity building from the Government's Skills for Life campaign.
"All this is most disappointing."
But the report did acknowledge a "dramatic improvement" in work-based training over the past four years, with inadequacy rates falling from 58% in 2001/02 to 25% in 2004/05.
Link with schools
David Sherlock, ALI's chief inspector, said adult education colleges were being forced to make up for the shortcomings of state schools.
"We cannot get away from the fact that the adult learning sector is distorted to deal with the shortcomings of our schools system," he said.
David Sherlock: Disappointed with the situation
"Until we deal with our failure to properly equip so many young people for adulthood, let alone successful careers, we cannot hope to build a world-beating adult skills strategy."
Skills minister Phil Hope acknowledged that there was much more to be done, but said the report had highlighted major improvements in the quality of training.
"The report will be a spur to help us identify what needs to be done to raise the quality of provision across the board," he said.
"More than a million adults have improved their skills and gained a first qualification since we launched the Skills for Life programme.
"We are on course to meet our target of improving the skills of 2.25 million adults by 2010."