On Monday Qatar Airways launched a new daily route to Doha from the capital via Sydney. Flights to Europe currently start at $1025, and the service offers connections to 150 destinations, including across Africa and the Middle East.

Flight centre ACT and NSW manager Dan Heathwood said Canberra's market had become highly competitive as a price war broke out between the Middle-Eastern carrier and Singapore Airlines, who first opened Canberra up to overseas travel in 2016.

For those willing to skimp on luggage, Fairfax unearthed fares with Qatar Airways as low as $889 return to London.

At Singapore Airlines, an all-inclusive trip to London was currently on sale with prices starting at $1,323. Canberrans can fly direct to the carrier's hub in Changi, and then on to a further 135 destinations, while return flights travel home via Sydney.

"I don't think fares have ever been this affordable, especially long-haul," Mr Heathwood said. "And demand is growing."

A spokesman for Singapore Airlines said fares tended to drop each year around January and were based on "market demand".

"Since launching international flights to Canberra in September 2016 we have seen strong growth in demand from Canberra and the surrounding region," the spokesman said.

That was why, just a month before Qatar Airways landed, Singapore Airlines announced a major overhaul of its ACT services.

While it's direct route to New Zealand will end come May 1, the carrier has instead ramped up flights to Singapore in a new daily service.

An arms-race in luxury is also underway. Singapore Airlines will switch its Canberra aircraft to a Boeing 777-300ER, allowing customers to fly first class and premium economy for the first time. And on Monday, Qatar Airways unveiled its new Qsuite business class which features double beds and adjustable private cabins for up to four people.

Senior manager of Australasia for Qatar Airways Adam Radwanski said, as other aircraft in the fleet were retro-fitted with the design, Qsuite would become a permanent fixture of the Canberra route.

Qatar Airways advised travellers to book before March 7 to claim discounted fares to Europe while London flights late in the year with Singapore Airlines crept back up to the $1800 mark.

Standard fares to Paris at the airline were about $1600, the spokesman said.

Mr Heathwood said there was nothing to suggest international fares from Canberra would drastically go up, but said travellers should "get in quick".

"You never know with flights, but certainly at the moment it's brilliant for Canberra."

Unlike Singapore Airlines, Qatar Airways does not have an open skies agreement with Australia and is restricted to 21 flight frequencies per week into Sydney, Melbourne, Brisbane and Perth airports.

The airline has rejected suggestions it is using Canberra as a "back door" into Sydney, with a 70-minute stopover in the city on the new ACT route.

Chief executive Akbar al-Baker said he would prefer to fly direct, but Canberra's runway fell short of the required 4300 metres for outgoing long-haul flights.

He has also flagged his desire to build a five-star hotel in Canberra.

Canberra Airport managing director Stephen Byron said the airport's masterplan allowed for another 600 metres to be added to the main runway.

However that would only take the runway to a length of 3883 metres.

The airport has welcomed the two airlines' international routes as proof of Canberra's growing tourist appeal.

- With Katie Burgess