Massachusetts hospitals are facing off against the state’s top nurses’ union over a bill that would lower nurse-patient ratios. The bill is likely headed for the November ballot if the state legislature doesn’t act.

Hospital officials claim boosting the number of nurses to patients would add expenses, without improving the quality of care. Steven Bradley is head of government relations at Baystate Health. He says the bill would add $500 million to annual health care costs statewide. He says for Baystate, “it’s $20 million in extra costs, and we would have to find an additional, say, 200 nurses to meet those requirements.”

Bradley notes this isn’t the first time nurses have pursued patient ratio legislation, and past efforts haven’t been successful. But this time, the union might have more leverage: they’re poised to make the issue a ballot question in November.

“The legislators have a few months to act, and if they don’t, the voters will decide,” says David Schildmeier, a spokesperson for the Massachusetts Nurses Association.

The union is also pursuing a ballot initiative aimed at limiting the salaries of hospital CEO’s.