The United States was facing a wave of strikes by fast-food workers today, a day after President Barack Obama warned that inequality in the country had reached the point that it posed "a fundamental threat to the American dream".

Low-paid workers in McDonald's, KFC and other fast-food outlets in 100 cities across the US were to start rolling strikes in protest at the low level of the country's US$7.25 ($8.83) an hour federal minimum wage.

The strikes are the latest part of a publicity campaign for higher wages among those working in so-called "McJobs".

Fast-food restaurants are seen as a pressure point that highlights the question of income inequality.


Last week, during the annual Black Friday Thanksgiving shopping day, US labour organisers said workers staged walkouts and protests at 1500 Walmart stores, calling for the company to raise wages and improve conditions.

Obama recently supported Democrat calls for a US$10.10 minimum wage, which was voted down by Republicans in Congress last March, but which campaigners say is the bare minimum needed for a single worker to survive.

Obama yesterday said that since the 1970s, the "basic bargain" at the heart of the US economy - work hard, get ahead - had been "frayed" by the many global economic forces that opened the door to union-busting, outsourcing and corporate greed.

"[There] is a dangerous and growing inequality and lack of upward mobility that has jeopardised middle-class America's basic bargain that if you work hard, you have a chance to get ahead.

"I believe this is the defining challenge of our time: making sure our economy works for every working American."

Framing his call for higher wages in history, Obama cited the upward mobility of Abraham Lincoln, whose father lived in a log cabin; Teddy Roosevelt's fight for an eight-hour working day; and Lyndon Johnson's introduction of the Medicare and Medicaid healthcare programmes.

He echoed the arguments of campaigners who claim that productivity gains by US workers, which have more than doubled since 1968, have not been passed on to workers, while pay for chief executives has sharply risen. "The top 10 per cent no longer takes in one third of our income; it now takes half.

"Whereas in the past, the average chief executive made about 20 to 30 times the income of the average worker, today's chief executive now makes 273 times more," he said.

The call for greater equality and fairer pay, which was at the heart of Obama's re-election campaign last year, is also set to be a key battleground of next year's mid-term elections. Polls suggest 80 per cent of Americans want to see a higher minimum wage.

Restaurant industry officials said the increase in workers' pay being demanded by the protesters would backfire on workers, forcing outlets to raise prices, cut down on hiring and rely on automation. Scott DeFife, of the National Restaurant Association, said the industry was "one of the few that continued to create jobs during the recession and economic recovery".