The Spanish capital is bracing for large anti-austerity protests as demonstrators from all over the country plan to march in downtown Madrid. By mid-morning several major roads had been blocked as buses unloaded protesters at 10 rendezvous points from which marches are to begin, The Associated Press reports.

The main organizer, Social Summit, an association of more than 150 organizations, and the Workers' Commissions and General Workers trade unions, say the demonstration protests government cuts during the country's financial crisis.

The government said it expects more than half a million people to reach Christopher Columbus Square where union leaders are to deliver speeches.

Marchers who arrived early on Saturday unfurled banners with slogans such as "Let's go! They are ruining the country and will have to pay for it."