Olivier Lepick, who is mayor of Carnac in western France, said he didn't know the significance of the 40 menhirs, which were thought to be about 7,000-years old.
Mr Lepick gave planning permission for the Mr. Bricolage DIY chain to knock them down in August last year to make way for a new shop. Following criticism, the mayor said allowing them to be knocked down was an "administrative error".
The stones were up to 100cm tall and were about a mile from the main Alignement de Carnac, which is a huge archaeological site that is about 1,000 years older than Stonehenge.
The formation has thousands of standing stones that range across 27 communes.
Local amateur archaeologist Christian Obeltz criticised the move to knock down the menhirs in his blog, which was later picked up by local and national media.
Mr Lepick said he received advice that the menhirs were of "low architectural value" and that granting a building permit was within the law.
He also said that he wasn't aware that the 40 menhirs were part of the wider site, despite being said to have led a group that applied for UNESCO world heritage site status for them last year.
But archaeologist Mr Obeltz said that officials hadn't carried out proper examinations before the permit was given.
Stéphane Doriel, who runs Mr. Bricolage DIY, said: "I’m not an archaeologist, I don’t know menhirs; low walls exist everywhere. If we’d known that, we’d obviously have done things differently."
The destruction of the menhirs has also sparked fury among French politicians and campaigners.
Marine Le Pen, leader of the right-wing party Front National, said: "We’re witnessing a series of failings. The state no longer protects our fellow citizens or our heritage. Appalling."
Her fellow hardline right-winger Eric Zemmour said in a video that "we destroy the past, and we plaster over it".
Marc Le Fur, an MP for the Conservative Les Républicains party, said: "How could the town allow such a massacre to take place on the site of the megalithic alignments of Carnac, at a time when all Breton elected officials are mobilising to have them listed as a World Heritage Site?"
Ecologist MP Sandrine Rousseau chimed in: "Destroying thousand-year-old menhirs for a store. What better illustration of our madness?"
Mr Lepick said the reaction was overblown - as if he had "destroyed the Mona Lisa".
"Everything is in place for me to get lynched," he told Le Monde, adding that he and his family were under police protection.
"They threatened to burn my house," the mayor told local media. "They threatened to kill me for being a traitor," he added.
"One of my daughters, aged 20, even received messages targeting me on her personal Instagram account. I’m angry to see my wife and my children accused and threatened."
The newspaper said the media coverage of the incident had turned Mr Lepick into "the most hated man in France" overnight.
https://www.lbc.co.uk/news/mayor-bulldozes-french-stonehenge-diy-hated/
