Pakistan's national airline has given overweight flight attendants an ultimatum to slim down or be grounded.

A waiver currently allowing Pakistan International Airlines (PIA) cabin crew to fly despite not meeting strict weight targets will be phased out over six months, staff were told last week.

The state owned carrier, which is sometimes accused of being bloated and inefficient itself, said the crackdown would ensure staff were “slim, smart and fit”.

The amount of excess weight tolerated will be cut from 30lb at present to 25lb by the start of February and then gradually reduce to nothing by July.

All staff would be weighed where they are based and the results would be kept “for perusal of management”, according to a January 1 memo from the general manager of flight services.

Those not measuring up will be grounded and sent for medical evaluation and treatment, the Aamir Bashir said.

Staff must already measure up to detailed weight targets depending on their height and whether they are considered to have a small, medium or large frame.

According to guidelines, a 5ft 7in woman of “medium frame” should weigh no more than 147lbs, or 10-and-a-half stone.

The airline had received passenger complaints that some cabin crew were obese, a spokesman told CNN.