Ontario Health Minister David Caplan will officially resign on Wednesday. (Jacques Boissinot/Canadian Press)

Ontario's health minister has resigned one day before the release of a report into spending scandals at an agency tasked with creating electronic health records in the province.

A Health Ministry representative told CBC News that David Caplan intends to officially step down on Wednesday. Officials in Premier Dalton McGuinty's office said they could not confirm the report until then.

Caplan quit because of what will be in the provincial auditor general's report, which is expected to detail the $1 billion Ontario has spent over 10 years trying to create electronic health records, sources told The Canadian Press.

"I think it tells you a lot about Dalton McGuinty — after six years in office — that he dodged, delayed, and stonewalled until backed into a corner," said Ontario Progressive Conservative Leader Tim Hudak, speaking about Caplan's resignation.

Auditor General Jim McCarter will release a 50-page special report, which was commissioned last June as the Liberal government tried to defend itself against revelations of millions of dollars in sole-sourced contracts and high-paid consultants' expense claims at eHealth.

Former agency CEO Sarah Kramer was fired in June, and eHealth chair Alan Hudson quit shortly after those details were publicized.

Opposition called for ouster

The opposition parties have been demanding Caplan's head since the expense details surfaced in April, and have criticized the government for axing senior bureaucrats but allowing a cabinet minister to keep his job.

Christine Elliott, the Conservative health critic, has said the scandal shows there is a lack of accountability in the McGuinty government.

The NDP also said Caplan had to resign if the government wanted to move beyond the eHealth scandal, and rejected the Liberals' defence that the problems covered in the auditor general's report will date back a decade, four years before they came to power.

McGuinty repeatedly defended Caplan as he came under fire over the summer.

Deputy Premier George Smitherman told the legislature Tuesday that governments of all stripes in the past allowed untendered contracts, but the Liberals changed the rules for all ministries and arm's-length agencies, boards and commissions to prohibit the practice.

"We've set a new standard and eliminated the prospect for sole-sourcing," Smitherman said.

"They did it. We've done it. It's been the pattern, but it's been changed and we've raised the bar."

EHealth was set up last September by the Liberal government, the merger of the e-health program at the Ministry of Health and Long-term Care Smart Systems for Health Agency (SSHA).

SSHA was created in 2003 with the goal of making a "secure, integrated, province-wide information infrastructure" to allow electronic communication between health-care providers. But an independent audit three years later found the agency lacked strategic direction and had made little progress in achieving its goals.

McGuinty opted for a fresh start and tasked eHealth last year with developing a similar digital record system by 2015 for health-care providers across the province to access.

With files from The Canadian Press