Watford MP Richard Harrington has described the shooting of two horses in Leavesden as a "terrible shame."
He said: "I have asked the council what procedures are in place to ensure that something like this cannot happen in the future, and they have explained that they receive a number of reports of stray horses or fly grazing every year and typically the horses are ‘green yarded’ or taken to a safe place while the owners are traced."
The Tory MP added: "This incident in Leavesden may be isolated, and in the extreme, but it is still understandably upsetting and very sad. I am awaiting further answers from the council and am happy to discuss this further with constituents if they would like to contact me."
Police were called to the scene after two stray horses were spotted by members of the public.
The Racehorse Rescue Centre is hoping the Conservative MP will support a petition that is demanding answers from the council over their handling of the case.
Nearly 7000 people have signed the petition that is questioning why a "gun wielding man on a quad bike" was allowed onto public land.
Nigel Wood, Chairman of The Racehorse Rescue Centre said: "The petition is nearly at 7,000 signatures now and we’re hoping for Richard to start an investigation into how the case was handled and the way the council did it."
He added: "It should have been done in a better way. It just wasn’t handled right."
Councillor Ann Shaw, Leader of Three Rivers Council, defended the council’s position.
She said: "Given the advice of the police and the equine body that advised us, I understand why the staff took the decision that they did."
The Liberal Democrat added: "I know that our staff had one idea and the police took another view.
Richard Harrington MP said: "The council believe that there was a very real danger to the public, including children considering the location, and that there was a very real risk of the horses escaping on to the A41."
Mr Wood said that the council and police should have consulted more with people with specialist knowledge of horses.
He said: "Whoever’s made the decision didn’t have a clue about horses and it just sounds like a reckless decision that was made without the proper information and support."
The charity chairman added: "Give them a bucket and feed, let them relax, let them calm down. Chasing them round all the time is just going to get them more and more wound up and that’s not the way to catch a horse, because they’re a flight animal and they’ll just keep running and running."