From today, 24 separate laws covering the state's gay and lesbian couples have changed - everything from protection against discrimination to who gets to decide on organ donation if a partner dies.

The changes are part of reforms to 43 separate pieces of legislation that will take effect between now and September, after State Parliament earlier this month passed the so-called Relationships Act.

Gay and lesbian activists have heralded the new laws, which followed a protracted political battle between the State Government and the Liberals, as the most advanced in Australia. They cover superannuation, next of kin issues, tenant rights and medical treatment questions.

Mr Rantzau hopes he will not have to feel the impact of the changes immediately, if at all: most are directed at emergency situations, such as when a partner dies without a will or a couple breaks up and the joint home has to be sold.

But he said yesterday that the reforms will help alter the way other people view his relationship with Mr Di Sciascio.  "I think it adds social recognition and legal recognition to our relationship. These are very important things. In many countries around the world it doesn't happen."

The changes are so important to Mr Rantzau that he went to parliament while the laws were being debated. "It was one of the few times when I could see parliamentary debate about something that directly affected me."

After a previous long-term relationship ended in 1997, Mr Rantzau had to pay stamp duty when he bought out his former partner's share of the house. That will no longer apply under the changes.

Attorney-General Rob Hulls said the changes were designed to make a difference to the ordinary daily lives of gay men and lesbians.

The act only passed parliament after the government agreed to make amendments to ensure support from the Liberal Party, which had previously opposed it. But the Nationals and independents Craig Ingram and Russell Savage refused to support it.

Today's proclamation has been chosen to coincide with Stonewall Day, the anniversary of riots against police at a New York bar in 1969 that is seen as the birth of the gay-rights movement.

Victorian Gay and Lesbian Rights Lobby co-convenor Miranda Stewart said today's date will also be remembered as a milestone towards equality.