A EURO-MP who came to see Huddersfield's library and art gallery said: "Why on Earth do they want to knock it down?"
Tory Timothy Kirkhope praised its "fine stone facade" and accused Kirklees Council of neglecting the building.
He was on a fact-finding visit as debate continues on the future of the 1930s library and art gallery.
Council chiefs have said at least £5m needs to be spent after major faults were discovered.
Mr Kirkhope, a Yorkshire and Humber Euro-MP, said: "This very fine stone building stands out even more because of the open aspect of its surroundings.
"Huddersfield is renowned for its many listed buildings and I am surprised that the library is not one of them.
"It is a very sad state of affairs when a council neglects to maintain its buildings and assets, as Kirklees is clearly guilty of in this case."
Mr Kirkhope also condemned plans to bulldoze Queensgate market hall only 30 years after it opened.
He said: "I hope the council will listen to public opinion, which I understand is heavily against knocking down the library.
"Demolition of a town's heritage is not the only answer to regeneration. It is a very extreme reaction which I am amazed has been put forward without extensive consultation taking place."
He was accompanied on his visit by Kirklees Council Tory group leader Clr Robert Light and deputy leader Clr Ken Sims.
Meanwhile, Labour councillors are upset that the library issue has not been put to the council's Huddersfield area committee.
Clr Ken Smith said: "I am disgusted that this most important matter for the town of Huddersfield has not been put on the agenda for discussion."
The council's ruling Liberal Democrats have promised full public consultation before any decisions are made about the library and art gallery building.
Related stories and messageboards