Lisbon: Hundreds of thousands protested in Portugal against austerity measures ahead of next week's talks with international creditors, with unions vowing to keep up the pressure.

Officials from the so-called Troika -- the European Union, European Central Bank and the International Monetary Fund -- will next week evaluate progress on the country's bailout programme.

Demonstrators arrived in Lisbon on Saturday from across the country in the rally described as one of the country's biggest in three decades.

Many were brandishing banners such as "The struggle continues" and "No to exploitation, no to inequality, no to impoverishment."

The CGTP union which called the march estimated 300,000 people took part, while police would not give any figures, in line with their usual practice.

"We are convinced that it is one of the biggest demonstrations in the last 30 years," said Armenio Carlos, general secretary of the CGTP, in a speech at the end of the protest in the landmark Praca do Comercio (Commerce Square).

He launched sharp attacks against the bailout conditions, calling them "a programme of aggression against workers and against the national interest."

"Austerity did not create wealth. The country needs the rope around its neck to be removed so that it can breathe, live and work," the unionist said, calling for a revision to the minimum wage of 485 euros gross.

"Net salary is at 432 euros, while the poverty line is at 434 euros, and that concerns currently ... 400,000 workers" in Portugal, he said.

He vowed that protests will continue in coming weeks, and that fresh demonstrations will be held across the country on February 29.

In exchange for a loan of 78 billion euros (USD 103 billion) from the EU and the IMF last May, Portugal agreed to sell public companies as well as implement labour reforms such as introducing shorter holidays.

However, many complain their lives have got worse.