Bill C-11 requires veterans' cases to be adjudicated to determine whether the injury is related to service before they're given statutory priority for jobs in the public service, Guy Parent said in an online blog.
"This could add additional red tape to the release process and potentially delay the ability to access priority hiring upon release," Parent wrote.
The proposed legislation says a veteran will qualify to go to the front of the line only if the disability was the result of service. Those medically released for non-service-related reasons will not get priority.
There are other uncertainties, including whether National Defence or Veterans Affairs will do the adjudication, what documents will be used, and how long it will take, the ombudsman said.
He says the idea of veterans getting faster access to federal jobs "encouraging."
The bill was introduced two weeks ago when the Conservatives faced rising public criticism over a growing number of wounded soldiers discharged before they have the 10 years service that gives them a pension.
Parent said the proposed legislation will create separate classes of veterans for federal priority hiring, a situation many in government and the veterans community have been striving to avoid.
"I believe that all medically releasing Canadian Armed Forces members should be treated the same way," he wrote.
The notion that there is just one veteran, regardless of when they served and their circumstances, was at the heart of the rewrite of benefits for ex-soldiers in 2006 under the New Veterans Charter.
"However, the proposed legislation does not follow this approach," Parent said.
"By elevating the priority for service-related medical releases, but not for non-service-related ones, it creates separate classes of veterans for priority hiring which will add an additional layer of complexity to an already overburdened system."
A spokesman for Veterans Affairs Minister Julian Fantino said details of how the legislation will unfold are still subject to debate.
"The operational changes and improvements that would flow from this newly tabled legislation are currently being finalized by Veterans Affairs Canada and the Public Service Commission, and every effort is being made to ensure veterans have quick and efficient access once implemented," said Joshua Zanin.
Cutting red tape for ex-service members has been an aim of the Conservatives, and Zanin says the legislation "complements" the government's existing efforts.
Federal budget documents show 496 veterans were on the public-service priority hiring list in 2011-12, of which 158 were appointed to federal jobs.
Soldiers let go for medical reasons have had a leg-up on federal jobs since 2005, but there was no guarantee in law. In addition, they could only take jobs turned down by other federal employees.
The new legislation applies to soldiers released on or after April 1, 2012, and extends the amount of time they have to apply for federal jobs to five years from two years under the current system.
The union representing defence workers described the bill as a knee-jerk reaction and warned that government should take care of its laid off and displaced civilians first.