Health services in NSW have been told they will need to find savings of $252 million under a new "treasury cap", which paramedics and health workers say will lead to cuts in emergency services and longer hospital waiting times.

Health districts across the state have been told by the state government that "NSW Health will collectively be required to achieve cost savings of $252 million" this financial year, according to documents leaked to NSW Labor and seen by the Herald.

The savings are part of a new "treasury cap" that will be introduced "across government agencies" and "will increase over the next three years", according to the leaked presentation.

Of the $252 million, $150 million are expected to come from local health districts, $67 million from ambulance, pathology and HealthShare, and $35 million from the Ministry of Health and the Cancer Institute.