The Morrison government has promised to generate 450,000 jobs through the JobMaker program.

But only 45,000 of jobs supported through the $4 billion hiring credit scheme will be new.

Shadow treasurer Jim Chalmers said Labor was always sceptical the scheme would create hundreds of thousands of jobs.

"Something like 90 per cent of those jobs that the government claimed aren't actually going to be created by this program," Dr Chalmers said on Tuesday.

"They've given false hope to 400,000 younger workers in this country, which is pretty shameful of itself."

Youth Minister Richard Colbeck said he did not provide any specific input into the hiring credit scheme.

"But I have been talking to my colleagues over a period over time about ensuring that we had a priority on managing youth measures," he told a Senate estimates hearing.

It has also emerged the Morrison government's claim of more than 500,000 jobs being created from two other major initiatives was not based on Treasury advice.

The government said its energy security road map would create 130,000 jobs by 2030.

As well, its manufacturing plan is being promoted as creating 80,000 direct jobs and 300,000 indirect jobs.

Treasury officials have confirmed the job figures for the energy plan were produced by the industry department based on advice from consultants.

Treasury also had no visibility over the figures used in the manufacturing plan.

Finance Minister Mathias Cormann said the industry department had the ability to do its own projections as one of the government's key economic agencies.

He said it was appropriate the industry department provided the figures.

Australian Associated Press