It comes as the Animal Justice Party is sending a letter – and a horse sponsorship, to Assistant Defence Minister Senator David Fawcett today. It is in an eleventh-hour bid to stop between 100 and 150 horses dying from bullets shot out of a helicopter.

Read more: Growing calls to halt aerial culling plans

The party says Senator Fawcett has the power to stop the aerial cull. 

The cull had been scheduled for December 18 and 19, according to Hunter Valley Brumby Association, which was tipped off about it. 

The Department of Defence told the Mercury its land management activities will be conducted at the base between December and January. It did not say whether aerial culling had been taken off the table.

The party’s Emma Hurst, who is also the national campaign director, penned the letter to Senator Fawcett and included a sponsorship of a rescue horse called Clancy, who is living at the Little Oak Sanctuary in the ACT.

“We hope that this gift encourages you to reconsider the proposed aerial killing of horses planned at Singleton army base.”

Ms Hurst will post the letter on Monday. 

She said aerial culling would tear the equine families apart and cause “unimaginably cruelty”.

“Aerial culling is exceptionally brutal,” Ms Hurst said.

“It cannot be done accurately, leaving many horses, including pregnant mares, and even foals, wounded and suffering long and painful deaths.”

The party has urged the government to consider the use of immunocontraceptive sterilisation. That involves shooting a dart at the horse which makes it infertile for a certain period of time. 

It is used to control wild horses in other countries.

Hunter Valley Brumby Association rescued two foals from the base in November.