Fare frenzy: Most popular flights from as low as $29
Australia's busiest air route of Melbourne to Sydney will also become the cheapest as an airfare war rages ahead of the launch of Rex's new services next month.
Days after Rex cut prices to $49 a seat one way, including baggage and refreshments, Jetstar has slashed its $105 fare on the route to $29.
The bargain fare will be offered for eight hours from midday on Friday for flights in late February to April, as part of a "fare frenzy sale".
Beyond that, Jetstar will sell one-way fares on the route from $39.
Virgin Australia has also weighed into the price war, matching Rex's $49 fare for flights in March only booked by the end of February.
In another blow to newcomer Rex, Jetstar will increase frequency on the route, with plans to operate 88 return services a week between Melbourne and Sydney by the end of March.
Rex has scheduled nine return flights a day, or 63 a week, as the regional carrier attempts to carve out a place in the competitive capital city market.
Jetstar has also cut fares on other routes for its eight-hour sale, with Brisbane to Cairns costing $79, Adelaide to Hobart $84 and Melbourne to Uluru from $89 one way.
A statement from Jetstar said the carrier was committed to always offering the lowest fares.
"If customers find a fare that is cheaper than the fare listed on Jetstar.com, Jetstar will beat it by 10 per cent," the statement said.
Airline executives have acknowledged that cheaper fares will be needed for some time to reinvigorate demand for air travel, devastated by the COVID-19 pandemic and border closures.
The latest domestic airfare index, compiled by the Bureau of Infrastructure, Transport and Regional Economics, showed discount prices were already at their lowest level in more than a year.
There were even greater savings to be made in business class, however, where fares were at an eight-year low of about two-thirds of normal prices.
Rex flights in Boeing 737 aircraft begin on March 1, providing state borders remain open.
The airline's deputy chairman, John Sharp, has warned that there will be "no point" to operating services on the route if travellers are restricted in any way. In the event flights are cancelled due to COVID-19, full refunds will be available to passengers.
Virgin Australia and Qantas are both offering passengers the option of changing flight times for free, right through to January next year.
Originally published as Fare frenzy: Most popular flights from as low as $29