Most of South Taranaki's largest companies have joined the opposition to downgrading Hāwera Hospital.
Taranaki District Health Board has proposed halving the number of beds at the hospital to 10 and moving six of the remaining beds to a rest home.
Instead of being at the hospital overnight, 24-hour emergency doctors would be on call.
At a DHB community meeting on Monday, resident Jean Pope presented a letter signed by managers of Fonterra, Vector Gas, Yarrows bakers, the Riverlands and Silver Fern Farms meatworks, two local engineering works and Origin Energy.
Ms Pope read part of the letter which said that 24-hour emergency department and base level of hospital services "should incontestably remain at Hāwera Hospital".
She said the companies argue that needless loss of life would otherwise result.
The district's mayor, Ross Dunlop, said last weekend's hostage-taking and police shooting in Opunake left Hāwera without ambulance cover.
He said he was constantly being asked, particularly by older people, whether it was safe to stay in the area or whether they should relocate to New Plymouth.
"This is undermining all of the good work that the council and others are doing to keep people here. We must restore confidence, urgently, in this community."