Dutch company Vion, which last week announced a phased closure of the plant would begin later this month, set a new deadline of noon tomorrow for offers for the site, which employs 1700 jobs.
Two unnamed bidders have expressed an interest, though it is not clear whether they want to take over the whole plant or only part of it.
Lawrence Wason, divisional officer with Usdaw, which has around 800 members at the plant, welcomed the extension of the deadline.
He said: “There is a glimmer of light.
“There certainly could be something salvaged, but it depends on it being a realistic viable bid.”