Governor Jerry Brown signed into a law a bill raising California's minimum wage from $10 to $15 (£10.50, €13) an hour by the year 2023, making the nation's most-populous state the first to boost pay to that level for the working poor.

The move marks the culmination of a deal Brown brokered with labour leaders and state Democratic leaders and puts California, home to one of the world's biggest economies, at the forefront of US states and cities that have moved to surpass the federal minimum wage, which has remained at $7.25 (£5, €6) an hour since 2009.

Brown said before signing the legislation: "So this is about economic justice, it's about people, it's about creating a little tiny balance in a system that everyday becomes more unbalanced. There's a lot of anger in the presidential campaign and it may have many sources, but one of the sources certainly is the way the average American is being treated by this particular economy."

"Today we do something about that in a very significant way, to sign into law the minimum wage of $15 an hour to give voice to the power and fervour and the belief of all the people standing here and all the people they represent. This is an important day. It's not the end of the struggle but it's a very important step forward. Let's keep it going, we're not stopping here," he added.

Both houses of California's legislature approved the measure on Thursday, fast-tracking proposed legislation announced two days earlier by Brown, a popular Democrat. The measure passed with no Republican support.

In New York on Monday (4 April), Governor Andrew Cuomo signed a bill that will eventually raise the minimum wage in New York City and surrounding areas to $15 per hour, tied in to economic factors such as legislation. Other parts of the state will see the current $9 per hour rate rise to $12.50 within five years.

Bernie Sanders seized on wage disparity as a defining issue in the presidential race. In a statement, Sanders said his campaign was about building on the steps in California and New York "so that everyone in this country can enjoy the dignity and basic economic security that comes from a living wage".