Captains of industry have criticised government proposals to improve modern apprenticeships as "seriously flawed".
In its response to the plans, the Confederation of British Industry warned that companies would be reluctant to recruit apprentices unless the scheme was made more flexible.
The government wants to introduce a requirement for a minimum amount of training time for apprentices, and to specify where the training takes place.
The CBI says it fully backs the objective to improve apprenticeships, which have attracted 140,000 16 to 24-year-olds so far, but have been dogged by low levels of achievement and high drop-out rates.
Susan Anderson, CBI director of human resources policy, said: "We want high-quality apprenticeships. We are four-square behind the idea of improvements."
But she added: "There are serious flaws in the proposals. It does not make sense to have unnecessary prescription about the time and location of training. Experience shows it would be better to give employers flexibility in these areas, with the government ensuring quality control."
The CBI added that the government would be wrong to pursue its proposal to guarantee an apprenticeship to all young people who are capable of completing a programme of training.
Ms Anderson said: "Apprentices should be in employment. There is no way the government can compel employers to offer young people places.
"Ministers can guarantee the quality of apprenticeships, but they cannot guarantee jobs."
More needed to be done to address the scheme's high drop-out rates - only about half of apprentices completed their training, the CBI said.
Too many young people joined programmes for which they are ill-prepared, because careers advice is inadequate, Ms Anderson said.
"We have to ratchet up the quality of careers advice in schools so all young people understand the options that are available," she added.