CHICAGO - Former Gov. Jim Edgar said Thursday that fellow Republican Judy Baar Topinka needs to raise at least $10 million to take on incumbent Gov. Rod Blagojevich in November.

Edgar said he doesn't doubt Topinka, a three-term state treasurer, can raise the cash, but Blagojevich can make it difficult for her.

"The only thing that would be a problem would be if Blagojevich would get a big bump here and then people would say, 'Well, the race is over,"' said Edgar, who is Topinka's honorary campaign chairman.

Blagojevich has been working hard to get that bump. Since the primary, his campaign has aired television commercials and the Democrat has traveled the state reminding people of the goals and accomplishments of his first-term.

Topinka and Blagojevich likely will spend between $23 million and $25 million combined in the run-up to the general election, said University of Illinois at Springfield political science professor Kent Redfield.

Redfield and Edgar were among the panelists at a luncheon to recap the March 21 primary that was sponsored by the Union League Club of Chicago and the University of Illinois' Institute of Government and Public Affairs.

Redfield estimates Topinka needs at least $8 million to finance her gubernatorial bid.

"I wouldn't want to try to run statewide with much less than that," he said.

The Topinka camp has said her campaign fund was nearly drained after a bruising five-way primary race for the GOP nomination. Topinka has promises of support from the Republican National Committee and the campaign has said it expects money from contributors to start rolling in in the coming weeks.

Topinka campaign spokesman Dave Loveday declined Thursday to say how much money they have and wouldn't comment on Edgar's estimate of $10 million needed. But he acknowledged it's unlikely Topinka will have as much money as Blagojevich, who barely cracked into his $15 million campaign fund during the primary.

Redfield estimated Topinka and Blagojevich spent about $3.3 million each during the primary. Final numbers will be known when campaign reports are filed in August, he said.

Edgar said national Republican party leaders can signal to others out of Illinois that Topinka has a legitimate chance to win and that they should step in to help. He said raising money in-state against an incumbent governor is tough.

"The national party is not so much the money, it's the signal they send to everybody else that this is the place you ought to put your money," he said.

Also Thursday, the Blagojevich campaign announced the governor has accepted an invitation to appear April 28 on WMAQ-TV's "City Desk" program and encouraged Topinka to accept as well.

Loveday said Topinka plans to debate Blagojevich before the November election but had not yet accepted any dates to do so. The governor, who declined to debate his primary challenger, has challenged Topinka to a series of 10 debates.