Microsoft Corporation has made a $100,000 (£62,976) donation to gay rights campaigners in Washington.

Next month, the state will hold a referendum on whether gay couples should be given expanded rights under domestic partnerships law.

The law, known as the ‘Everything but marriage’ measure, was due to come into power in June but was put on hold due to the referendum campaign, known as R-71.

Microsoft, which is based in Redmond, made the donation on Tuesday to Washington Families Standing Together. It is thought to be the single largest donation in favour of the pro-gay campaign.

The referendum is being held on November 3rd. If the state’s voters approve it, it will give gay couples all the rights afforded to heterosexual couples, such as adoption and child support rights.

Currently, the law provides gay couples with only some of the benefits given to straight married couples. Almost 6,000 domestic partnerships have been filed since 2007, which the law was passed.

According to Associated Press, the fundraising and spending of the ‘approve’ campaign dwarfs that of opponents.

Washington Families Standing Together has raised approximately $780,000 overall and spent about $200,000.

Protect Marriage Washington, which is campaigning against the new benefits, has raised around $60,000 and spent about $35,000.