Barton cafe owners say they're losing money and customers as a direct result of food trucks being set up in the parliamentary triangle.
The food trucks were set up on the Parkes Place lawn earlier this month as part of a trial by the National Capital Authority to bring more people to the precinct during spring.
However, cafe owners within the triangle say their businesses took a hit during the week when the four food trucks were operating in the area.
Priscilla Ong, the owner of the cafe Barbers Inc, said she, along with other cafe owners, were not informed of the decision by the authority to bring more competition to the parliamentary triangle.
"We had no idea that this was happening," Ms Ong said.
"It does worry me and it affects our bottom line. We did take a hit."
The food trucks set up in the parliamentary triangle during the first week of spring, and will return to the area in the first week of the month in October and November.
The authority previously said they would consider expanding the trial should it prove successful.
Ms Ong said business was starting to pick up after the end of winter but there was a sharp decline of customers in the week the food trucks were operational.
"A lot of our business comes in the spring weather, and there was a noticeable drop in customers," she said.
"There are a number of cafes throughout Barton and we're the ones in the area paying rent and have to keep areas clean.
"We're servicing the business district of Barton on a daily basis."
Cafe owners met with the authority last week to outline their concern with the food trucks setting up in Barton.
A spokeswoman for the authority said they were working alongside businesses.
"With each new event, the NCA is adjusting the mix and presentation with an aim to create a series of activations that benefit the wider community," the spokeswoman said.
"The food trucks are appearing on a trial basis to activate Parkes Place.
"This is on the back of email and face-to-face conversation with six eateries facing or directly impacting Parkes Place.
"None of those businesses expressed any concerns leading up to the event."
Dennis Toulis, the owner of Coffers Cafe in the Treasury building, directly opposite the site of the food truck, said he was not informed of the decision to install the food trucks.
"We were disappointed about the decision," Mr Toulis said.
"The week the food trucks were there, it was like not being paid for a week's worth of work."
While business was impacted during the week the food trucks were operating, Mr Toulis said business and sales were back to normal the following week.
"When a decision such as this is made, people have to think of the impact of it."
The authority spokeswoman said the food trucks were part of a broader plan to bring more people to the parliamentary triangle, and had proved to be successful.
"Many of these events are creative ideas and activities that should appeal to a broad range of Canberrans and tourists alike, including sporting events, music and culture, food and wine," the spokeswoman said.
The food trucks are set to return to the precinct on September 30.