Museums in the north-east of England could "fall by the wayside" as a result of the coronavirus outbreak.
Long-term financial support is needed to offset the economic impact of the lockdown, culture managers say.
Tyne and Wear Archives and Museums (TWAM) is in talks to secure urgent grants, a strategic board meeting was told earlier.
The government has said it is "committed to supporting" the cultural sector across the country.
Current estimates suggest the organisation could face a shortfall of more than £340,000 this year.
Revenues have plummeted as museums have closed amid the lockdown and visitor numbers are expected to be well down on normal levels when they reopen.
Additional costs are expected to come from the extra cleaning and provision of protective equipment needed for staff while social distancing measures are in place.
Newcastle councillor Ged Bell warned the culture sector across the country needed to ask for help "collectively" as well as at regional and local levels, the Local Democracy Reporting Service said.
"There is a need for the government to assist us here or I feel that a lot of cultural offers across the country could actually fall by the wayside," he added.
TWAM manages a number of museums including Newcastle's Discovery Museum and Laing Art Gallery, as well as South Shields Museum.
Director Iain Watson said it was "talking actively" with the National Lottery Heritage Fund and the Arts Council over their emergency funds, which are aimed more at organisations that are in immediate crisis and cannot pay staff at the end of the month.
Earlier this month the Department for Digital, Culture, Media and Sport said an "unprecedented government package" aimed to provide help for museums and the arts sectors.