Michael Bloomberg, the independent mayor of New York City, has described marriage equality as a “fundamental civil right”.

In a speech last night, he urged state politicians to legislate on introducing gay marriage immediately.

Mr Bloomberg, who once opposed gay marriage, came out in favour of the issue in 2005, citing his lesbian niece Rachel Tiven.

“When I meet a New Yorker who is gay, when I speak with … family members and members of my staff who are gay, or when I look into the eyes of my niece, Rachel,” he said. “I cannot tell them that their government is correct in denying them the right to marry.

“I can’t tell them that marriage is not for them. I can’t tell them that a civil union is good enough.

“In our democracy, near equality is no equality. Government either treats everyone the same, or it doesn’t. And right now it doesn’t.”

Mr Bloomberg said that he recognises the “pain the status quo causes.”

In a question pointed at state legislators, Mr Bloomberg asked: “Do you want to be remembered as a leader on civil rights? Or an obstructionist?”

“On matters of freedom and equality, history has not remembered obstructionists kindly. Not on abolition. Not on abortion. Not on women’s suffrage. Not on workers’ rights. Not on civil rights. And it will be no different on marriage rights.”

In 2009, the state Senate rejected a bill to allow gay couples to marry by 38 votes to 24. Earlier this month, Andrew Cuomo, the governor of New York began a tour of the state highlighting his legislative priorities including marriage equality.