It is understood senior staff in some departments began changing "program" to "programme" in their briefs for incoming ministers, even before they were sworn in.

Yet there is now widespread confusion in Canberra about how to write the highly politicised word.

Prime Minister Tony Abbott's office says it has not told the public service to alter the spelling.

However, his preference for the longer word is well known, and several ministers' offices demanded last month that their departments get with the "programme", so to speak.

Some public servants have since begun changing text on websites and in government documents, though others are holding fort and awaiting further instruction.

Former prime minister John Howard issued a memo after he won office in 1996, telling the bureaucracy to avoid what he thought was the American "program" in favour of the British "programme".

(In fact, the English had used "program" for hundreds of years – it appears in Shakespeare's works – and only switched en masse to "programme" during that era of francophilia, the 19th century.)

After Kevin Rudd led Labor to power in 2007, he reversed the edict.

The government's latest Style Manual makes no explicit ruling on the spelling, though it refers to "program" throughout.

Senior public servants had noted the Coalition used "programme" consistently in opposition and began preparing for a switch in August.

When Mr Abbott issued a media statement on September 18 that contained "programmes", several agencies interpreted it as an instruction and told staff to change their spelling.

Some bureaucrats have expressed frustration at the work created by the apparently whimsical switch; one senior officer told Fairfax Media it was "trivial f---ing nonsense".

The Australian National Dictionary Centre's director, Amanda Laugesen, said on Wednesday that a return to "programme" was odd.

"It's an old-fashioned way of spelling it and it would be unusual to adopt it. But I don't know what dictates the public service's decisions."

The centre, which advises Oxford University Press on its Australian dictionaries, adopted "program" recently though it notes "programme" is also acceptable.

"It's a shorter word, it's more efficent and that's the way spelling tends to head," Dr Laugesen said.