MPs have warned that expanding apprenticeships by giving every teenager the right to a place could "consign the programme to the dustbin" without measures to guarantee quality.
The select committee on innovation, universities and skills said the draft apprenticeships Bill did not do enough to ensure that the status of apprenticeships was maintained as a valued route to a future career, with numbers due to expand to 400,000 by 2020.
Setting out the need to monitor, promote and report on the quality of apprenticeships, the committee quoted the evidence of David Frost, director general of the British Chambers of Commerce: "Simply to go for volume at the expense of quality will just consign this programme to the dustbin."
The committee also set out concerns that the Bill failed to tackle the issue of supply of apprenticeship places during an economic downturn. It called on the Government to set out how it expects the public sector to provide and organise apprenticeships during the recession, and what additional resources will be available.
Jim Knight, the schools minister, said this week that he expects every school in the country to take on at least one apprentice teaching assistant. Several colleges already recruit apprentices to work for them.
Small businesses also need help with the administrative work of setting up and running apprenticeship programmes, the committee said. It recommended that the Bill is amended to require the new National Apprenticeship Service to fund group training associations - not-for-profit bodies to help local businesses with training.
The committee also criticised the draft Bill for omitting important information, including the specification of apprenticeship standards, setting out the core elements of all apprenticeships, such as the amount of on-the-job training.
It also lacked details of how the National Apprenticeship Service would be funded and organised, and did not set out how the legislation would apply in Wales.
Phil Willis, the committee chairman, said: "The focus on increasing the volume of apprenticeships must not be done at the expense of quality. We urge the Government to make clear in the draft Bill how it will ensure that quality is guaranteed. If quality falters, no one will want to become an apprentice.
"It is a challenging time to be introducing employer-led apprenticeships, particularly for small businesses, and every effort must be made to ensure they are supported and receive the necessary help."
The children, schools and families select committee, which also published its verdict on the Bill, said it had "grave doubts" that the statutory right to an apprenticeship could be met in a recession, and shared the skills committee's concern about pressure on quality.
It said success in increasing the number and range of apprenticeships depended on the public sector, where MPs believed there would be many junior posts in hospitals, colleges and schools that would be suitable for apprentices.
The committee also questioned the need for some of the Bill's provisions, intended to raise standards in apprenticeships. It agreed with the aim, but said it could have been achieved without legislation.
Ministers said it had "symbolic importance" to enshrine in legislation the value of developing skills, but the committee suggested "symbolic" Bills were not a good use of Parliamentary time.