Updated

New York City Mayor Michael Bloomberg is leaving the nation's biggest mayoral job with a glowing view of the future of cities. But he's also issuing a stern warning that they face a dangerous threat: public worker health care and pension costs and the politics around them.

Bloomberg gave what's envisioned as the last major speech of his 12-year tenure Wednesday to The Economic Club of New York.

He has said previously that rising pension and health care costs imperil progress in New York and other cities. But he painted the issue Wednesday in dramatic terms. He lashed out at what he called a "fiscal straitjacket" for cities and a "labor-electoral complex that has traditionally stymied reform."

Bloomberg has clashed with unions. Most city employees are working with expired contracts.