Should public parks be free for all or it is fair that businesses operating from the grounds pay a fee for the space?

Debate has erupted after Perth's Kings Park announced groups using the grounds for fitness classes will have to pay a fee from November 2.

The 1,000-acre park close to the city centre attracts almost 6 million visitors a year, and the Botanic Gardens and Parks Authority says that trainers running fitness groups in the park are putting pressure on space and parking.

The authority's chief executive Mark Webb said that many local councils had introduced fees for group training sessions and some fitness groups had moved to Kings Park to avoid the fees.

"We welcome use of Kings Park, formally or informally," Mr Webb told John McGlue on 720 ABC Perth.

"We are trying to manage the organised fitness groups' use of the park so that it doesn't negatively impact on other users of the park.

"Many groups want to use the Fraser Avenue precinct and that means we are trying to manage high demand in a fairly limited area.

"Kings Park is a large place, but there are some parts of the park we don't allow organised fitness, like the State War Memorial and the Botanic Gardens."

Walking in Kings Park Botanic Gardens. The park authority is concerned that exercise groups are impinging on other users of the park. ( 720 ABC Perth: Emma Wynne )

Kings Park will charge $100 for four one-hour sessions in six designated areas in the park and will monitor the system to assess if the fee structure is working.

Currently the adjacent City of Perth council charges $80 for a three-month permit for groups of 10 or more to use the city's parks for fitness classes.

The City of Stirling in the northern suburbs charges up to $2,200 for an annual permit.

"What we want to do is charge organised fitness groups, which tend to be 10-25 people, for using an area of Kings Park and try and make sure there are not too many groups in one area," Mr Webb said.

There will be no charge for groups of people who get together to jog or play a game of soccer where a fitness trainer is not being paid to run the session.

Some 720 ABC Perth listeners supported the idea while others thought it was unfair.

Em via SMS: "This is absolutely ridiculous! Live and let live, for heaven's sake! And if neighbours object to any sounds of energetic folks having a good time — then how do they cope with raucous parrots etc?"

Steve: "Commercial users should pay. Otherwise tax and rate payers pick up maintenance costs."

Linda: "Kings Park even charges for the use of a gazebo for a birthday party so exercise groups should pay too."

Mr Webb said the authority was also aiming to manage parking in Kings Park with the booking system.

"At different times, in the morning and late afternoons, it is very difficult to get parking in Kings Park for people who just want to come in and have a look around," he said.

"Some of this is driven by people using it for organised fitness groups and also by people who use the park as free parking then go into West Perth or even down to the city.

"There is signage in Kings Park saying if you park there you must be using Kings Park."

Mr Webb said the park had had problems for years with visitors using free parking to go to the nearby Jacob's Ladder staircase to exercise and that rangers would issue warnings and fines.

"It's important that we leave the parking free for Kings Park visitors," he said.