Young female staffer who had an affair with Liberal minister Alan Tudge claims his cabinet colleague forced her out of politics with a 'fake redundancy' as punishment

A former adviser has accused federal Employment Minister Michaelia Cash of forcing her out of her office through a 'fake redundancy' process.

Rachelle Miller says she was punished because of her affair with another cabinet minister, Alan Tudge, who she had worked for previously.

Ms Miller has accused Senator Cash of months of poor treatment during the first half of 2018.

The complaint says Ms Miller felt ambushed in April 2018 with a request to go on leave, was asked whether personal issues were undermining her work, and was excluded from meetings.

A former adviser has accused federal Employment Minister Michaelia Cash of forcing her out of her office through a 'fake redundancy' process

Population Minister Alan Tudge had an affair in 2017 with former Coalition media adviser Rachelle Miller. The two are pictured together at the mid-winter ball in 2017

In June 2018, Ms Miller was told the office was being restructured and her role would be made redundant.

Ms Miller was told she could apply for a more junior role.

'It was very clear that this was a fake redundancy process put in place to get rid of me from the office,' she wrote in a complaint to the Department of Finance.

'There were no grounds for this, there had been no performance management process put in place, nor had I received formal warnings.'

Senator Cash denies Ms Miller's claims.

'The minister strenuously rejects claims of any adverse treatment of Ms Miller by her, or her office, and strongly disputes Ms Miller's version of events,' a spokesman told AAP.

Ms Miller told Four Corners she has lived 'to bitterly regret' the affair with Mr Tudge

'At the time of her employment, between late 2017 and mid-2018, the minister and the office understood Ms Miller's personal circumstances which is why support, leave and flexible work arrangements were offered to her.

'Given the matter is now subject to a formal process in the Department of Finance, the minister will not be commenting further.'

Ms Miller has lodged a separate complaint against Mr Tudge, accusing him of bullying and intimidation.

She now works in the private sector.

Mr Tudge's spokesman said he was not aware of any previous complaint and directed further enquiries to the finance department.