Thousands of fast food workers held demonstrations across the United States today, protesting against low wages in front of McDonalds, KFCs and Donut shops. 

They came out at dawn in cities such as New York, Miami and Philadelphia to ask the giants of the restaurant business to raise their wages. 

Though labour organizers aimed to make this an international day of protest, for now at least, this is largely a US fight, with only small scattered protests in Europe.

New York protesters called for a minimum wage of $15 so workers could live on their salary without public programs such as food stamps.

One protester, picketing outside a McDonalds, said she wanted “a better living wage for everybody, more respect, more dignity.”

The campaign for better pay and working conditions has been waged over the last 18 months, with a round of protests last year.

Organized campaign

"Workers are saying look, we've been working hard, we've been working longer hours, we're more productive than we were several decades ago," said Jack Temple a policy analyst for the National Employment Law Project. "But it hasn't paid off in terms of higher wages. So with our backs against the wall, workers are saying the next step is to walk off the job, to organize." 

In March, for instance, lawsuits filed in three states accused McDonald's of engaging in practices that deprive workers of their rightful wages, such as the denial of breaks and overtime pay. Workers were referred to lawyers by union organizers, who announced protests over "wage theft" the following week.

President Barack Obama has been working to raise the federal minimum wage to $10.10 an hour. The current rate of $7.25 an hour translates to about $15,000 US a year, assuming a person works 40 hours a week.

Fast-food workers have historically been considered difficult to unionize, since many are part-timers or teenagers who don't stay on the job for long. Also complicating matters is that most fast-food restaurants in the U.S. are owned by franchisees who say they're already operating on thin profit margins.

In a statement, McDonald's noted that the actions were not strikes and that outside groups "travelled to McDonald's and other outlets to stage rallies."

The National Restaurant Association called the actions "nothing more than big labour's attempt to push their own agenda."

Inequality a hot issue.

But in the U.S., the issue of wage inequality is becoming a hot-button issue, especially when executive pay continues to soar and the federal minimum wage has been unchanged for four years.

“Fast food workers and nurse assistants and retail sales people who work their tails off and are still living at or barely above poverty,” Obama said in a speech advocating a higher minimum wage.

Action on the issue has stalled in Congress. But 13 states have raised their own minimum wage since the beginning of the year.

Business leaders such as former Hewlett-Packard CEO Carly Fiorina have campaigned against a wage hike. “Here’s the truth about minimum wage. It will help some people who already have a job. I will hurt people who do not have jobs,” she said.

But today Wal-Mart Stores Inc. said it wouldn't oppose an increase in the federal minimum wage.

"We are not opposed to minimum wage increase, unless it’s directed exclusively at us," said Wal-Mart U.S. President Bill Simon.

With files from the Associated Press