Qantas passengers with unused travel credits could be given longer to cash them in, as the airline fends off concern the cash is propping up its bottom line.

Flight Centre chief executive Graham Turner said on Wednesday there was a good chance the national carrier could defer the date for the expiry of travel credits issued at the height of the COVID-19 pandemic.

It came amid a storm after outgoing Qantas boss Alan Joyce told a Senate committee earlier this week that the value of the airline’s flight credits was $100 million higher than the $370 million reported, with $100 million in credit yet to be redeemed by Jetstar customers.

No amount has been given for overseas bookings.

Mr Joyce’s revelations came just days after Qantas revealed a record $2.47 billion profit.

The credits are due to expire at the end of the year.

But Mr Turner said it was in Qantas’ best interest to extend the deadline to allow passengers more time to redeem them.

“Qantas will probably extend it again. They’ve extended it three times, just because the lack of capacity means that if people want to transfer on another flight or book other flights, it can be quite hard to get a booking when you wanted,” he told Seven’s Sunrise program on Wednesday.

“Some of these credits come back to three years old, and after a year a lot of the records are purged. So it is difficult [to redeem], particularly people who booked directly online.”

Prime Minister Anthony Albanese has said people who booked flights with Qantas should be able to reuse the credit.

“If people have booked flights and paid money, they should either get access to another at another time or receive their money back,” he said in Adelaide on Tuesday.

Qantas is rolling out a major communication program to alert passengers to the expiring credits.

The government has also come under fire for blocking additional Qatar Airways flights to Australia after lobbying from Qantas.

Virgin Australia chief executive Jayne Hrdlicka has said allowing the flights – from which her company would benefit due to its partnership with Qatar Airways – would cut fares by up to 40 per cent.

On Wednesday, Mr Turner agreed the extra flights would lead to lower international airfares.

“We desperately need more capacity and this was not a good decision from our point of view,” he said.

Former head of the consumer watchdog Allan Fels said the government’s move meant less competition in the industry.

“[The government’s rationale] is to look after Qantas. Customers have been put second – so has tourism, business freight, many other interest, also other airlines,” he told ABC TV.

“There’s no secret reason for it, it’s just looking after Qantas.”

Professor Fels said the Australian Competition and Consumer Commission should investigate the Qatar Airways decision.

Opposition finance spokeswoman Jane Hume said the government was running a protection racket for Qantas.

“We’ve had such inconsistent messaging on this. If it really was in the national interest, why is it in the national interest?” she said.

“No company should be protected from competition, particularly when Australians are relying on an organisation like Qantas which, let’s face it, operates with a fair degree of social contract.”

Earlier this week, the government appeared split in its defence of the decision to block Qatar’s bid. Assistant Treasurer Stephen Jones said it was intended to ensure Qantas was profitable.

But that contradicted statements by Transport Minister Catherine King, who ultimately made the decision last month. Ms King said on Monday she disagreed with Mr Jones’ characterisation.

– with AAP