One of Auckland's oldest Thai restaurants will be closing after being severely impacted by the Auckland City Rail Link (CRL) construction and coronavirus outbreak.

Mai Thai, which opened for business in 1989, has been steadily losing customers since the CRL works began - but owner Bow Manoonpong says the sharp drop in tourist numbers was "the straw that broke this camel's back".

The Restaurant Association said many restaurant owners are now in "desperate situations" with many facing temporary closures.

Mai Thai is the second longest running Thai eatery in the city, with the oldest being Red Elephant on Khyber Pass Rd - previously known as Chang Thong - which started a year earlier.

Mai Thai on the corner of Victoria St and Albert St will close for good at the end of April. Photo / Alex Burton

Manoonpong said the restaurant, famous for its pad thai noodles and tom yum goong, will shut its doors for the last time at the end of April.

"It was such a difficult and painful decision to make, but we didn't have any other choice," said Manoonpong, who started the business when she was just 26.

"We have had many good memories here, and Mai Thai is happy to have been the pioneers in bringing authentic Thai cuisine to Aucklanders."

Mai Thai has won the Thai Select award for the past 15 years, and queues to get into the 160-seater restaurant were a common sight in the past.

The restaurant has hosted former Thai Prime Minister Yingluck Shinawatra and her officials during her visit to New Zealand, and has been regarded as the "official venue" for dinners by visiting Thai delegations and officials.

But since works began for the city rail link, the once bustling Albert St had been turned into a massive construction site.

Recent travel and immigration restrictions due to the virus also meant tourists and international students have almost vanished in recent weeks.

"When tourists stopped coming there was no way we could survive, and since our lease was also up for renewal we thought this was time to say goodbye," Manoonpong said.

"I problems started with the CRL, but I think the coronavirus situation is what broke this camel's back."

In its last month of operation, Mai Thai will be donating $2 from each main dish it sells to Starship Hospital as a way to thank Aucklanders for their support.

Red Wall 1939 in Parnell which offers Chinese fine dining has also shut. Photo / File.

Restaurant Association chief executive Marisa Bidois is calling on Kiwi locals to continue dining out or risk losing more ethnic restaurants.

Two fine dining Asian eateries that opened last year, Red Wall 1939 at the Parnell Rose Garden and Epicer by Michelin-star chef Manjunath Mural on Ponsonby Rd, have also closed down.

"We are fielding a number of calls from business owners in desperate situations, asking for advice as they face temporary closure. Many of these calls are coming from our ethnic restaurants," Bidois said.

"These restaurants are struggling on two fronts; a lack of international tourists particularly from China where group bookings in Chinese restaurants are common during the summer period and also from local diners staying away for fear of being exposed to the virus."

Epicer by Michellin-star chef Manjunath Mural has closed down. Photo / File.

Bidois said the association had in the last two weeks received calls from Chinese, Indian, Thai, Italian and also Iranian restaurants which seemed to be the most affected.

"These businesses are feeling largely unheard. We are doing all we can to assist with our free emergency membership to businesses that need it," she said.

"We enjoy a vibrant and diverse dining scene in New Zealand and we want to see that continue so we urge local diners to continue to dine out."