The unusual octagonal building , built in 1971, will be razed to make way for a larger library and records office (above) as well as 110 flats, a park and an office building as part of Cambridgeshire County Council's £30 redevelopment of the Princes Street area of the town.
However, English Heritage refused to list the building, claiming it was of 'only modest architectural quality' and on Monday night (21 May) the district council approved the scheme.
The decision has not been welcomed by David Hufford, a spokesman for Huntingdon and Godmanchester Civic Society Committee. He said: '[The current library] is the best piece of modern architecture in Huntingdon. To lose this is a real tragedy.
'If a building like this cannot be adapted it doesn't say much about modern architecture. It was claimed the building was no longer fit for purpose but it is perfectly adequate and to knock it down is a criminal waste.
'Most people are amazed to learn it is going to be totally destroyed,' Hufford added. 'And what is going in its place is really disappointing.'
But county council spokesman Glenn Thwaites was adamant that the current facilities were not up to modern-day standards.
Thwaites said: 'We receive regular complaints from library users about both the building and its facilities.
'Because of its design, which was appropriate in the 1970s, it was impossible to improve the facilities to match either modern library requirements or customer expectations.
'The new library will be in a state of the art building which meets the aspirations for a 21st century facility and we're delighted to be able to make these improvements,' he added.
Work is expected to start on site this summer.