Under plans being considered by transport minister John Spellar, firms would be obliged to take on a minimum number of trainees or face exclusion from government civil engineering contracts.
This could see contractors shut out from the government's £60bn, 10-year transport plan.
Whitehall sources say Spellar is determined to avoid a repetition of the problems on the Jubilee Line Extension in London two years ago, which were caused mainly by the shortage of skilled workers and rocketing pay demands.
At one point, project manager Bechtel agreed to pay electricians working on the JLE £2000 a week.
Spellar is understood to want to protect taxpayers from having to foot the bill for similar hikes.
In his first week in his job, Spellar is understood to have made the creation of a skilled workforce in construction a key tenet of policy.
One Whitehall official said Spellar believed that contractors needed to be cajoled into investing in training.
The official said that the department would try to reach a consensus with contractors' leaders on the level of the quotas before the initiative was launched.
But the source said: "The principle of contractors that fail to meet the target being excluded from contracts is non-negotiable."
Employers' body the Confederation of Construction Clients said such a policy would help the industry to achieve the target of a having one half of the workforce trained by next year.
Executive secretary Tony Pollington said the proposals were fully in line with CCC policy and would give clients the confidence to employ staff knowing that they were likely to be competent.
He said: "Although this measure would be confined to central government contracts, ministerial backing on such initiatives must be seen as a positive step."
Cambridge University's director of estate management, David Adamson, added that the plans were also in line those of more progressive clients.
He said clients now sought evidence from contractors and specialist contractors on the quality of their workforces at the tendering stage.
He added that the process would be in line with the Construction Industry Training Board campaign to get contractors to put people on training courses.
A spokesperson for the CITB said it had not spoken to Spellar about his plans. But he said: "It comes as no surprise that Spellar should be implementing such measures as he is a former union man within the construction industry."