The Coombs shopping centre developer Renato Cervo on Wednesday did not want to discuss the matter but did say the centre would be open for business "very soon". Mr Cervo also said he was working seven days a week on the project and doing the best he could.

Mr Cervo technically has until 2019 to have the centre open, under the conditions of a development application approved by the government in late 2016.

The centre is still under construction. It includes room for a supermarket of 1000 square metres, a cafe and retail shops.

Residents say a sign erected out the front by Mr Cervo spelling out that the centre was "established 2015" graphically illustrated the long wait for some local shops in the burgeoning suburb.

Mr Cervo bought the site at auction in 2015 and lodged a development application the same year, hoping for an opening by mid-2016. He has blamed objections to the original centre design as the reasons for the delay.

Local resident Damian Breach said the ACT government should have ensured the quick delivery of a shopping centre to the fast-growing suburbs of Molonglo, at least by determining its development through an open tender rather than public auction.

"I've sent two emails to [Planning Minister] Mick Gentleman and had no response. We feel let down," Mr Breach said.

"It would be good to get a response from the government, not just, 'It's not our business'.

"They have a responsibility to the community to ensure this infrastructure is delivered in a timely manner."

Opposition planning spokesman Mark Parton said he was "not surprised residents are frustrated".

"Canberra's planning system is far too complex, making it difficult even for planning officials to navigate," he said.

"The planning system should provide certainty for Canberra developers and the community but time and time again we see the opposite is true."

A spokesman for Mr Gentleman said Mr Cervo had two years from the start of building to finish the shopping centre, which gave him until early 2019. The timing of the opening of the building was then "a commercial decision".

"The site for Coombs shops was sold in good faith that a supermarket would be constructed and opened in reasonable time. Planning and land release facilitated a desirable outcome - however if the proponent fails to deliver, it appears subsequent developments may take up the opportunity to provide a supermarket," he said.

Residents' anxiety about the future of the Coombs shops comes as a rival developer is looking to build another shopping centre literally across the road, in Wright.

Called Koko Molonglo, the proposed development on the other side of John Gorton Drive promises a 1500 square metre supermarket and "confirmed retailers including a hair salon, eateries, bike retailer and bike workshop".

A publicity campaign for Koko Molonglo has begun before a development application has been lodged, with developer John Krnc declining to comment as yet.

"Public consultation will be a part of this [DA process], so the community will get an update as soon as have some real plans," Mr Krnc said, in an email.

The spokesman said the site for the rival supermarket was at Block 1, Section 38 in Wright.

"The Suburban Land Agency confirm this CZ5 zoned site was sold in December 2017 with no special conditions restricting use. The market should determine the most viable use. In this case a supermarket is a permitted use, however it is understood the lessee is still seeking a tenant and has not yet submitted a development application or participated in pre-app[lication] discussions," he said.

Residents, meanwhile, were also concerned a chemist would not be able to be located in the Coombs shopping centre due to pharmacy guild rules related to the size of the supermarket.

A spokesman for the Pharmacy Guild of Australia said a new chemist must be within 500m of a full-time, prescribing medical practitioner and in a centre with a supermarket, which had a gross leasable area of at least 1000 square metres.

A medical centre is due to open close to the Coombs shops.

The guild's spokesman said the federal health minister could also also use his or her discretion to override the rules if the proposed pharmacy was in an area of unmet community need.

Coombs residents Alison and John Hutchison said the ACT government did a good job delivering a local school quickly and could not understand why the local shops were taking so long.

Mrs Hutchison said the lack of shopping centres in Molonglo was putting pressure on the next available large centre, Cooleman Court in Weston, particularly parking.

"If I mention I live in Coombs, people say, 'When are you people getting your damn supermarket? We're sick of you filling up the parking lot'," she said.

Mr Breach said there were many Facebook groups set up about issues in Molonglo.

"And this is the most common thing complained about - 'Where are the shops? Where are the shops? Where are the shops?'," he said.

The residents say they felt the suburbs were being treated differently to the city in terms of the level of infrastructure including retail outlets in newly-developed areas.

"As one of my friends says, 'There are no cash registers in Coombs - or Wright. Not one," Mr Hutchison said.

Meanwhile, Capital Estate Developments, which is building a new shopping centre at nearby Denman Prospect, initially promised to have the complex open by late 2017, saying it would be fast-tracked to fill the void left by the Coombs shops not yet being opened.

"Capital Estate Developments will fast-track the Denman Prospect Shopping Centre delivering local shopping to Molonglo Valley residents by late 2017," a statement at the time read.

However, that deadline has since been revised, with Capital Estate Developments saying since early 2017 that the Denman Village Shops will be open in September this year.