The Governor of Illinois has signed the state’s same sex civil-union legislation into law. The move comes after a state senate vote to recognise same sex unions.

The state, home to Chicago, with one of the largest LGBT communities in the United States, passed legislation to introduce a formalised relationships on a par with British civil partnerships in December 2010.

“Today is an important day in the history of our state because today we are showing the world that the people of Illinois believe in equality for all,” Governor Pat Quinn said after signing the legislation into law.

“We look forward to individuals and businesses from across the country choosing to move to Illinois where we believe that everyone is entitled to the same rights.”

Gay couples in Illinois will gain some of the rights associated with marriage but their relationships will not be recognised under federal law. New Jersey also has civil unions. Oregon, Nevada, Hawaii, Maine, Wisconsin and the state of Washington extend some of the rights of married couples to gay relationships through domestic partnership laws.

But five states – Massachusetts, Connecticut, Iowa, Vermont and New Hampshire as well as the District of Columbia allow full gay marriage and campaigners in Illinois said this is their ultimate goal.

Jacob Meister, president of The Civil Rights Agenda, a gay rights organisation, told AP that civil unions would give gay couples essential rights but added: “The ultimate goal is not to be separate but equal.”

Campaigners in the UK are to challenge the ban on same sex marriage and opposite sex civil partnerships in the European Court of Human Rights.