Delays and cancellations have become regular occurrences

On Thursday, angry passengers staged a protest on the Tarmac in Brasilia.

In recent days up to 44% of flights have been delayed or cancelled, according to the authorities.

The problems started in October when air traffic staff began a work-to-rule protest following the deaths of 154 people in Brazil's worst plane crash.

Air traffic controllers say they are overworked, underpaid and understaffed, putting safety at risk.

Authorities are still investigating whether controllers had a role in the 29 September disaster.

It's not acceptable that a passenger stays three, four hours at the airport without any explanation President Lula

Earlier this month, passengers suffered days of disruptions after take-offs were banned from three of Brazil's major airports because of a failure in air traffic control systems.

Passenger action

Speaking at a news conference on Thursday, President Luiz Inacio Lula da Silva said: "This problem must be solved once and for all.

"It's not acceptable that a passenger stays three, four hours at the airport without any explanation."

The latest problems - which coincide with increased passenger volumes because of the Christmas holiday - were blamed on heavy rains in the Sao Paulo area, which led to the temporary closure of Brazil's busiest airport.

The problems were exacerbated when a number of planes from Tam, the country's largest airline, were hit by maintenance problems.

Frustrated by the delays, several passengers in the capital, Brasilia, staged a protest on the Tarmac. According to local media they had been waiting eight hours for a flight to Buenos Aires, Argentina.

In Rio de Janeiro, a passenger was reported to have damaged a computer belonging to Tam airlines.