Federal NDP Leader Jack Layton is scheduled to have hip surgery at Toronto's Mount Sinai Hospital on Friday.

Sources told CBC News the 60-year-old's hip problem started as a micro fracture. He tried to walk off the problem, continuing to exercise and putting additional stress on the fracture.

After the pain increased, he went for an X-ray. Doctors determined it was a micro fracture and recommended Layton stop putting weight on one of his legs. He has been on crutches for a couple of weeks, but the fracture did not heal.

A full fracture developed, which will require surgery to remedy the situation, a source said.

Layton's health issue could rule out the possibility of a spring federal election, the Toronto Star reported Thursday.

A spring election could be possible if the NDP refuses to support the minority Conservative government's March 22 budget.

But Layton is expected to recover before the budget vote, Kathleen Monk, director of communications for the NDP, told the Star.

In the past, Layton has battled prostate cancer.