Dr Mahathir Mohamad said he did not need big luxury jets during his 22 years in power but added that perhaps the current government had more funds to afford such an indulgence.

Speaking at Angkasapuri after appearing on an RTM2 programme to mark his 11 years of retirement, the former prime minister said he even opted to downgrade his jet during his early years in office.

"In 1981, I inherited a Boeing 737 from the previous PM - he had problems travelling, so I can understand why he has to have a big plane.

"I used the plane for a short while and I asked them what is the cost. They told me it will cost the government RM2 million a year. Then (I decided) we sell the plane, I need a small plane. So it was reduced to a Challenger," he told reporters.

Last November, the Prime Minister’s Department told Parliament that the government now owns at least five planes, including a Boeing Business Jet.

The aircrafts, meant for use by VVIPs - including the prime minister and the Yang di-Pertuan Agong - comprise of a Falcon, Global Express, Boeing Business Jet, Blackhawk, two Augustas and a Fokker F28.

Minister in the Prime Minister's Department Shahidan Kassim said that in 2012, the costs for the jets were RM14.95 million in fuel and RM160.08 million in maintenance costs.

Mahathir was asked if he thought Najib's spending on jets were excessive.

'The government is much richer now'

"Well of course now, the government is much richer than during my time, then maybe they should upgrade" he said.

Later, Mahathir said, he did loosen the government purse on jet spending for practical reasons.

"Subsequently, I bought a slightly bigger plane because I had to travel slightly longer distances. But when I stepped down, I didn't have these big planes," he said.

He then recalled that his government did buy one Boeing business jet for the Yang di-Pertuan Agong.

"But that was not for my use," he quickly added.

Opposition MPs recently questioned why, despite calls for austerity measures and the cutting back of subsidies and raising of taxes to cure the government deficit, the prime minister and his wife Rosmah Mansor went around in private jets.

Defending the move, Rosmah said that her use of the government jet for a trip to the Middle East was referred to the cabinet and that her travels were for 'work' purposes.

She said this response to criticism of her use of the jet for the trip to Qatar , which was raised in Parliament by Gombak MP Azmin Ali.

Last week, pro-Umno bloggers also asked whether Najib had not one but two luxury jets in service, as an Airbus ACJ320 was reportedly leased to the government.

The Prime Minister’s Office said the lease of the Airbus ACJ320, which began on Feb 1, 2013, ended on Dec 31 that year.

The lease of the Airbus ACJ320 was necessary because of a shortage of government aircraft, it added.