Support for the Berejiklian government's proposed Sydney marine park reaches as high as 90 per cent in four coastal electorates, a result supporters hope will counter opposition from angler groups.

A ReachTEL poll of almost 2600 people in four coastal electorates conducted for the NSW Nature Conservation Council last Monday found 89 per cent support in Manly and 87 per cent in Coogee. Backing exceeded three-quarters in Gosford and Terrigal.

"Contrary to the claims of some lobbyists, the vast majority of people support the government's proposed marine park for the Sydney region," Sharnie Connell, Sydney Marine Park Campaign spokeswoman, said.

Environmental groups say there are worrying indications from within the government that it may be willing to shelve the long-awaited marine plan. They blame a concerted campaign by conservative talk-back radio hosts and angler groups against the proposed network of protected off-shore sites between Newcastle and Wollongong, and taking in part of Sydney Harbour.

"Most people polled last week in coastal electorates said they wanted at least 10 per cent of the region’s waters designated no-take sanctuary zones," Ms Connell said, noting that tally compared with just 2.5 per cent of the area now being proposed for high-level protection.