Mayor Michael Hancock said on Friday evening that he will veto a bill ending the city’s pit bull ban passed by Denver City Council earlier this week.

Hancock’s decision comes after his office received more than 900 emails and dozens of phone calls over the bill, according to a video statement Hancock released Friday afternoon. A group of residents also delivered a petition on Thursday requesting he veto the bill, citing concerns over public safety.

“After deep reflection and consideration, I find that I cannot, in good conscience, support this legislation and will exercise my authority as Mayor to veto it,” Hancock said Friday.

The bill, introduced by Councilman Chris Herndon, passed 7-4 on Monday and would have created a process for pit bull owners to lawfully keep their pets after they were banned in 1989.

Hancock said in the video statement that he grew up in Denver at a time when the city had multiple high-profile attacks by pit bulls.

Supporters called the bill a compromise on the original ban, and many who testified on Monday described pit bulls as affectionate and supportive family pets. Opponents characterized them as dangerous animals that would put children and the elderly at risk.

“I’m disappointed the mayor is choosing to disregard the science on the issue of breed-specific legislation,” Councilman Herndon said in a statement issued Friday. “Research tells us breed-specific legislation is ineffective at keeping communities safe and experts in the field – from the local level to the national level – agree it is no longer best practice. I hope my colleagues on Council will support an evidence-based approach to our animal ordinance, rather than one steeped in fear and stereotypes. The community has demonstrated significant support for this proposal and should it not pass on Tuesday, I look forward to working on a measure for the November ballot.”

City council can override the mayor’s veto with nine votes. The bill passed with seven votes, but council members Stacie Gilmore and Candi CdeBaca were absent.