By Dominic Giannini in Canberra

The Australian Defence Force is thousands of people below strength as it struggles to employ and retain staff.

There was a shortage of more than 4300 people – almost seven per cent – as of January 1, Chief of the ADF Angus Campbell told a parliamentary hearing.

Hiring rates are below the level required to maintain the force, the general said on Wednesday.

“Defence is addressing retention and recruitment as a priority,” he said.

A tight labour market made the task more difficult.

On the plus side, the number of people leaving the force dropped from a high of almost 12 per cent to 10 per cent in February.

There were also struggles with skill sets within the staff shortage number, General Campbell said.

The army, air force and navy were all under “varying degrees of stress”.

But the size of the air force was at a two-decade high, the Australian Defence Force Academy just started one of its largest intakes of trainee officers and the army graduated its largest cohort from the military college last year.

There had also been an 85 per cent take-up of the $50,000 retention bonus trial put in place to help keep staff.

Department officials also came under fire after admitting it took 300 days for a recruit to join the army after signing up.

Defence was working to bring that down to 100 days, chief of personnel Lieutenant General Natasha Fox said.

“I have an additional task to accelerate recruiting and make that faster than 100 days,” she said.

“That includes all the medical, psychological and security checks.”

Liberal frontbencher Simon Birmingham pursued questions about the Department of Defence’s culture following reports of tensions between minister Richard Marles and top brass.

The issue traced back to a tense meeting between the minister, department secretary and defence chief.

“There won’t be any Valentine’s Day cards flowing between the minister for defence and his department, though, will there?” Senator Birmingham said.

Defence Secretary Greg Moriarty said it wasn’t unusual for a minister to make clear their expectations of senior staff.

“I’ve had many interactions with a number of ministers in this portfolio and it’s routine and, in fact, appropriate for them to have these engagements with the department,” he said.

“The minister also set out areas where he was very pleased with the performance of the department.”