The baker, Ali Parnian, said he had been targeted for refusing to pay protection money to local organised crime.
An initiative to raise money to cover the cost of damage to Parnian's business was started by Conservative Party MP Mette Abildgaard.
"For me, this is about showing support for a man who made a very brave choice in saying 'no' to extortion," Abildgaard said.
The collection was initially intended to fund flowers and chocolates as a gesture of good wishes, but grew into something more, she added.
265,000 kroner had been collected by Monday night.
"Greetings and 235,000 thanks from Ali -- that's the amount of money that has been donated. Denmark is a fantastic country that sticks together when it matters!" the Conservative MP wrote on Twitter.
Jeg skulle hilse fra Ali og sige 235.000 gange tak. Så mange penge er der nemlig kommet ind. Danmark er et fantastisk land, står sammen når det gælder! 💪🏽❤️ 😊 pic.twitter.com/oUEl7SVyYe— Mette Abildgaard (@metteabildgaard) January 22, 2018
In a later tweet, Abildgaard revised the amount up to 265,000 kroner.
But she told news agency Ritzau that the case gives rise to deeper concerns.
"First and foremost, we must make sure that those responsible [for the vandalism] are caught. And I am looking forward to finding out whether this is a general problem in Tingbjerg," she said.
"Everything seems to suggest that [Parnian] and his business could not be insured. If that is true, it is completely absurd. If there are places in Denmark where you can't get insurance, that is something we must look at," she continued.
Copenhagen Lord Mayor Frank Jensen also pronounced his support for the baker.
"I can only condemn mafia methods like this and hope there are enough video recordings from the premises for police to be able to find the culprits and hold them responsible," he wrote.
The incident has been reported to police.
In 2012, Copenhagen Municipality carried out an investigation into the prevalence of extortion in the Nørrebro neighbourhood after similar reports emerged of the practice in that district.
"The finding at that time was that there was no sign of a general problem. But I would like to say that if anyone is subjected to [extortion], they should immediately go to the police or municipality with examples," Jensen said.
The episode cast a "grim shadow" over otherwise positive developments in the city, the mayor added.
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