Campaigners want the thousands to gather again on the steps of Halifax Town Hall next month when councillors debate plans to demolish the library at Northgate.
Anne Kirker, coordinator of the Don’t Bulldoze Our Library campaign, said: “We are back where we were in March 2009. Our campaign banner has been dusted off .
“We urge those 16,000 people who supported our earlier campaign to urge the council leader, cabinet members and councillors to reject this ill-considered proposal when they debate it on December 7.
“Join us on the steps of Halifax Town Hall when the meeting takes place.”
Councillors will debate whether to demolish the library and archive and replace it with a new glass-fronted building near the Piece Hall.
Mrs Kirker said: “The proposal to be placed before the council next month is a major one, with implications that will be far-reaching and long lasting for Halifax, Calderdale and the wider world,
“We feel there is no adequate foundation on which to base a decision to go forward with a replacement library.
Meanwhile it has been suggested building a new library beside the Piece Hall could cost up to £12 million.
That is almost twice what it would cost to refurbish the existing premises and has prompted Conservative councillors to question the move.
Now it wants answers to key questions about the costs involved and the lack of public consultation.
They plan to lobby the Calderdale Council meeting on December 7.
Conservative councillors say they are worried about the details of the scheme and the council’s apparent U-turn, having previously promised to retain the library.
Calderdale Council Cabinet was told it would cost up to £6 million to refurbish the Central Library and archives, and up to £12 million to refurbish the nearby council admin block, Northgate House.
According to Conservative group leader Stephen Baines, a new library and archive would cost almost twice that of restoring the current premises.
“Unfortunately I am not permitted to give details of the costs but would point out that the figures differ from those in a report to the cabinet,” he said.
“Northgate House is in a very poor condition and unsuitable, and should be re-developed for much needed retail space that fits the needs of businesses which want to expand into Halifax.
“But this can be done and a refurbished Library kept in its current position,” said Coun Baines (Northowram and Shelf).
*Halifax MP Linda Riordan has asked the council to set up a “full, open and transparent” consultation process regarding the library and the Northgate site.
“People want to express their thoughts, some have concerns or want more information about the plans - you cannot rush such an important decision,” she said.