Liberal Leader Michael Ignatieff says he cannot promise sweeping changes to the employment insurance system, despite an agreement earlier this week with the Conservatives to review the program -- a deal that averted a summer election call.

"We're working towards a solution," Ignatieff said Sunday on CTV's Question Period. "I'm going to try in good faith to get there. I can't give you any guarantees we're going get there, but I'm going try."

On Wednesday, Ignatieff and Prime Minister Stephen Harper agreed to establish a six-member panel to review EI and report back to Parliament on Sept. 28.

Ignatieff and Harper will each appoint three members to the panel. Ignatieff has selected MPs Marlene Jennings and Mike Savage and his chief policy Kevin Chan. Harper has so far only announced Human Resources Minister Diane Finley will be joining the panel.

The deal was reached following the opposition parties' dismay over the Harper government's economic progress report, which was delivered on June 11.

Contained within the report's 234 pages were claims that 80 per cent of stimulus spending was being implemented and 3,000 new infrastructure projects were already underway.

The opposition parties initially threatened to bring down the government over four issues: EI reform, stimulus spending, the growing deficit and the medical isotope shortage.

However, after three closed-door meetings with Harper, Ignatieff decided to let the Harper government survive for at least the summer on the promise that the EI system would be reviewed.

Ignatieff said he had no regrets about allowing the decision, although some critics said he could have forced more concessions from the government.

"Coulda, shoulda, woulda -- don't want to go there, Craig," Ignatieff told Question Period host Craig Oliver. "What I'm concerned about is to see whether it's possible, with a government with whom I have serious disagreements, to get something good for Canadians that is a substantial -- not a minor, not a tinkering -- but a substantial reform of EI that moves us towards national standards."

The Liberals have called for national EI standards that would set the eligibility mark at 360 hours.

The party also wants the self employed to become eligible for EI.

Ignatieff warned that if that there aren't sweeping changes to the system, the Liberals will be forced to "reconsider our options."

"We're not going to go on and on forever here," Ignatieff said. "This thing has a fixed deadline. We must achieve results for the Canadian people. If we can't then we're going to have to reassess the situation."