Ministers will join forces with companies who are willing to back a voluntary commitment to support their staff upgrade their skills.

Skills Envoy Sir Digby Jones, who will join the launch, branded the lack of basic skills in both the public and private sector as Britain's "shameful and unspoken secret."

He said: "With seven million adults who are functionally illiterate and 11 million who cannot add up two three figure numbers, the social and economic cost of an unskilled adult population is fundamentally damaging to Britain's chance of winning in the 21st century.

"This summer, after 11 years of full-time, compulsory education, virtually all of which will have been on this government's watch, half of those taking GCSEs will not get Grade C or above in English and Maths. This is an unacceptable, national disgrace."

But David Frost, Director General of the British Chambers of Commerce, said the pledge was not the right way to increase training in the workplace.

"We support the Government's drive to ensure that employees receive training that helps them in their careers but employers tell me that this pledge is unhelpful and patronising.

"The overwhelming majority of businesses are committed to training their staff, albeit not always through standard qualifications as often these do not meet their needs. However, they are concerned that the pledge will mean that essential public resources will be diverted away from making the skills infrastructure simpler for employers to navigate in order to make sure that employers sign up to it."

Derek Simpson, joint general secretary of the Unite union, welcomed the move, adding: "Employers have a poor record when it comes to investing in training and development.

"We hope employers will take the skills pledge otherwise they may well face compulsion."