Business people descended on 10 Downing Street on Tuesday with a letter of protest from the Association of Learning Providers about the way training centres have been "devastated" by the closure of the scheme in November.
ILAs were scrapped amid allegations of fraud, mis-selling and the provision of poor-quality training by some companies.
Attendance at private computer courses in February was 42 per cent down on the same month last year, according to a survey of 200 centres.
Tory education spokesman Alistair Burt, who joined the delegation, said:
"The Government was warned that, unless quality control was a key part of the scheme, it would be prone to fraud and abuse. They did not listen."
The Commons education and skills select committee has been taking evidence on the way the ILA scheme was run and the circumstances surrounding its demise.
The committee, chaired by Labour MP Barry Sheerman, is due to report to Parliament in April and the Department for Education and Skills says it intends to create a replacement scheme.