It says the new restrictions, which come into force on 17 April, bring the airline “in line with the rest of the industry”.

The change, says the budget carrier, will “help manage overcrowding of overhead locker space, assist with passenger safety and comfort and enable efficiencies during check-in to enhance the airline’s on time performance”.

The new carry-on guidelines allow customers to carry a maximum of two free bags provided they do not exceed 54cm X 38cm X 23cm or a total combined weight of 7 kg per person.

Passengers who want to bring on board extra luggage will have to purchase additional carry-on baggage allowance – to be known as Cabin+ – of up to a total of 12 kg.

This new Cabin+ product ( which costs $18 for shorter flights and $23 for longer flights, or at check-in for $36 for shorter flights and $46 for longer flights) will enable passengers to have two carry-on items with a maximum combined weight of 12 kg per passenger in total, provided they do not exceed 54cm X 38cm X 23cm.

The new baggage allowance limits will apply for all domestic flights booked from 17 March 2015 for travel from 17 April 2015. For all flight bookings made prior to 17 March 2015 or for travel prior to 17 April 2015, the 10kg baggage allowance is still applicable.