A report that the government has asked the public service to search for fresh spending cuts before Christmas sparked vitriol on Monday between ACT and federal MPs.

The Community and Public Sector Union said many public sectors workers would have taken comfort from the Prime Minister's promise not to ''slash and burn'' the federal bureaucracy.

The union's assistant national secretary, Louise Persse, said federal public servants were feeling the pressure from previously announced budget cuts and the increased efficiency dividend.

''The last federal budget took $2.2 billion out of the Commonwealth public service and we estimate that more than 5300 Commonwealth jobs have been lost since November 2011,'' she said.

''It is not possible to make cuts like this without damaging services. The community has a right to expect decent services and these cuts have gone far enough.''

The recent budget update - the midyear economic and fiscal outlook - set aside an additional $95 million to pay public servant wages, with Customs and the Taxation Office needing to recruit staff to beef up surveillance activities.

The State of the Service report last week said the public service continued to grow this year despite the toughest crackdown on spending in more than a decade and at a time when many agencies were retrenching staff.

Labor's Andrew Leigh said the government was always asking how it could do its work better, without cutting jobs.

Canberra's public servants should not be concerned by a Liberal Party fear campaign.

Liberal Gary Humphries suggested Mr Leigh was living in a parallel universe if he did not believe jobs were being cut.

''Clearly if Andrew Leigh thinks there aren't any cuts, he's living in a different Canberra to the one I'm living in,'' Senator Humphries said.

Cabinet's expenditure review committee - the ''razor gang'' - is meeting to find savings that will fulfil the government's pledge to return the budget to surplus this financial year.

Dr Leigh said he did not think there was room for further job cuts.

''Canberrans should not be concerned by a Liberal Party fear campaign,'' he said. ''We should focus on the fact that last Friday The Canberra Times reported on its front page that public servant numbers are at record highs.''

Asked for an assurance of no further public service job cuts, he said: ''Look at the facts would be my response to that.

''The State of the Service shows there are 168,000 public servants, a record number of public servants because there's an awful lot to do.

''We recognise that if you're going to do things like a National Disability Insurance Scheme and the Gonski reforms, that needs public servants to do it. We'll always focus on finding efficiencies through other means than jobs. I've always believed that cutting jobs should be last thing we do.''

Senator Humphries said a close study of MYEFO found nothing about making the government more efficient.