Professional shooters may fail in reaching their target for the capital’s annual kangaroo cull by the July 31 deadline, following repeated legal delays by activists.

The program had been given the green light after a decision handed down by the ACT Civil and Administrative Tribunal on Wednesday, ruling that 1244 kangaroos could be shot by the end of July. A further interim application lodged by the Australian Society for Kangaroos on Friday was dismissed.

ACT Municipal Services Minister Shane Rattenbury confirmed on Monday that culling operations had begun, but the delays had left a narrow window for shooters.

“No doubt this will have an impact on the original target,” he said.

“… There are a few factors against reaching that original target.”

Speaking on ABC Radio, Mr Rattenbury said “minor adjustments” had been made due to the presence of activists across the seven sites.

“There have been protesters on site,” he said.

“I believe some warnings have been issued, but I’m not aware of any major incidents at this point.”

Activists had vowed to disrupt shooting across the reserves – Callum Brae, Goorooyarroo, Kama, Mount Painter, Mullanggari, Mulligan’s Flat and The Pinnacle – but those caught trespassing could be fined up to $5500 under the Nature Conservation Act.

Animal Liberation ACT spokeswoman Carolyn Drew said activists had been out over the weekend since shooting on Friday evening, but she contradicted Mr Rattenbury's claims that warnings had been issued.

"We were sitting there from 10.30pm till 5am waiting," she said.

"As far as I know, no fines or warnings were issued."

An ACT Government spokeswoman confirmed that one written warning had been issued as of 2pm on Monday.