Scores of residents stormed out of a council meeting over plans for a luxury cat hotel which they claimed poses a "life-threatening" health risk.
Perfect Paradise was granted permission to look after up to 16 cats at a time on Hartwood Road in Southport.
A residents' spokesman said approval of the cattery could be "a matter of life or death" for asthma sufferers.
But Sefton Council's planners accepted the owner's pledge to keep the pens clean and approved the development.
A petition against the cat hotel was signed by 158 people, with a further 12 individual objections from people living nearby.
Signatories raised a number of issues, including noise, smells and air pollution from minute animal dust particles, the Local Democracy Reporting Service said.
Mr Farrington, who lives on Hartwood Road, told councillors: "I make no exaggeration when I say the approval of a new cattery could be a matter of life or death.
"Dander [dead skin cells that cats naturally shed], for anyone suffering from asthma, can be life-threatening.
"The particles are a tenth of the size of a dust mite and therefore cannot be filtered. If the council approves this development, they'll be putting the health and welfare of local people in jeopardy."
But owner Tiffany Donaldson said the cattery meets all DEFRA guidelines and that Environmental Health have raised no concerns.
She said each part of each pen would be cleaned thoroughly on a daily basis and kept "immaculate".
Objectors also claimed the cattery business would cause traffic and parking problems in a residential area.
Council planning officer Kevin Baker said the proposal was acceptable in respect of its impact on neighbouring properties and highway safety.
The cattery plans were approved by Sefton's planning committee with restrictions on operating hours.