A motion has been tabled in State Parliament to allow the Premier, Lara Giddings, and Greens Leader, Nick McKim to co-sponsor a bill to introduce marriage equality in Tasmania.

Ms Giddings said she had agreed to take the historic step to co-sponsor the bill with Mr McKim.  A motion is required for the Parliament to grant leave for a co-sponsored bill to be tabled.

"The decision to introduce a co-sponsored bill has been made in recognition that both Labor and the Greens have a strong and long-held interest in this important social reform," Ms Giddings said.

"Through this bilateral approach we can send a strong message to the rest of the country that the time has come to end this last example of discrimination against same-sex couples.

"While this is a complex area of law reform, we are committed to introducing legalisation as soon as possible."

Also today, Ms Giddings welcomed the ACT Government's stated support for marriage equality as proof that the time has come for change.

Ms Giddings said the Tasmanian Government was prepared to work with the ACT Government where it could to progress marriage equality laws.

"It is fantastic that ACT Labor is following Tasmania's lead by investigating same-sex marriage laws.

"This follows commitments by both the governments of South Australia and the Northern Territory to grant a conscience vote on this extremely important issue.

"I firmly believe that society has reached a tipping point and that the time has come to end discrimination against same sex couples.

"It is heartening that a growing number of state and territory governments share the same view.

"The Tasmanian Government is prepared to collaborate with other governments to progress reform."