Representatives from the ACT Government briefed Greens attorney-general spokesman Shane Rattenbury yesterday on Labor's proposed changes, which it believes will make the Greens' Bill more palatable to the Federal Government.

The Rudd Government has already threatened to invalidate the laws under the Australian Capital Territory (Self-Government) Act because they ''mimic'' and undermine marriage between a man and woman, but Mr Rattenbury was hopeful the amendments could allay the Federal Government's concerns.

''I think the intention of the amendments are good, I think the motivations are strong, and I think they've been quite innovative in thinking about how we can overcome Federal Government concerns,'' he said yesterday.

Under existing civil partnership laws the ACT Government introduced last year ceremonies can be held but they are not legally binding. It is only the signing of a document that grants legal recognition to the union.

Mr Rattenbury's proposed laws sought to make the ceremony itself legally binding in the same way that a wedding ceremony is.

The ACT Government has twice sought to include such a provision but has twice been thwarted by the Federal Government, first by the Howard government in 2006 and again last year by the Rudd Government, which threatened to veto the whole Bill if such provisions were included.

In a bid to avoid the Federal Government disallowing the provision again, ACT Attorney-General Simon Corbell has proposed a compromise that would enable couples to back-date their official registrations to the date of their ceremonies.

This would make the ceremonies technically the legal start of their relationships without attaching the legal status to the ceremony itself.

Although he is confident an amended version of his Bill would pass in the Legislative Assembly when it is put to a vote on Wednesday, he would need to further consider some of the amendments before agreeing to them.