There will also be a crackdown on second jobs, social media use and sloppy appearances among the department's public servants as the Customs agency hierarchy tightens its grip on Immigration.

Immigration's 8500 public servants were told just before the Christmas break that they will be subject to the same "integrity framework" as their new colleagues in Customs as the two departments merge to form the "Australian Border Force".

Among the 18 major new workplace policies sent out for consultation were drug and alcohol rules allowing managers to carry out either random or targeted tests for alcohol or narcotics on Immigration bureaucrats as they work.

Public servants will be in trouble if caught with a blood alcohol reading above .02 or if they are found to be "impaired" by illegal or prescription drugs while on duty.

"The portfolio has zero-tolerance for the possession, use of trafficking of prohibitive drugs and DIBP and ACBPS are alcohol free workplaces," workers were told in a fact sheet.

"Workers found to be in breach of this policy can expect to face serious consequences including code of conduct investigations that can lead to the imposition of sanctions including the termination of employment."

Public sector union the CPSU says in a bulletin sent out to members that the new rules, due to come into force in March, are causing "significant concern" among workers at Immigration with public servants at the department due to begin holding meetings from mid-January to discuss their bosses' decision.

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However, a departmental spokeswoman said on Monday that the new framework was necessary to reflect Immigration's new "mission".

"In the context of the new department individual staff will be exposed to a broader range of vulnerabilities and risks," she said.

"Our integrity must be of the highest order and our behaviour consistent with the laws we enforce.

"While the vast majority of our combined workforce displays exemplary integrity, we must do everything we can to protect our workforce and our organisation from criminal influence and actions."

The framework has already been adopted by Customs as part of its ongoing battle to get on top of its internal corruption problems but is seen by Immigration public servants as another step in what is being referred to internally as the "Customisation" of their department.

A new mandatory reporting regime will require Immigration officials to dob-in colleagues they suspect of misconduct, even if it occurs away from the workplace.

Any work undertaken outside the department, even volunteering for not-for-profit organisations, must be reported to a public servant's bosses and a tough new social media policy will be imposed to prevent both security breaches and embarrassment to the merged department.

"Inappropriate use of social media, social networking services, or official email, instant messaging or online platforms could compromise DIBP staff and Customs workers and potentially their family and friends as well as jeopardise their careers," a briefing note stated.

There will also be a crackdown on sloppily dressed public servants with "dress-down" days banned and a prohibition placed on jeans, non-uniform shorts and revealing mid-riff tops while on the job.

Thongs, casual trainers and ugg boots also make the banned list with Immigration public servants also ordered to go easy on the make-up, cover tattoos and keep the hairstyles conservative.

Laying down the law: Immigration's new integrity framework