GREECE - The Greek parliament has passed reforms to the country's ailing social security system, sparking protests led by the country's two largest labour unions.

The new laws were adopted narrowly, with 159 votes for and 137 against.

Parliamentarians of the New Democracy, the Communist Party of Greece, the Christian People's Orthodox Rally and the Coalition of the Radical Left voted against the legislation, tabled by the ruling Panhellenic Socialist Movement Party.

The reforms are part of an austerity package Greece has adopted to deal with its budget deficit of 13.7% of GDP and a pension gap of €4bn.

The government said it aimed to bring the budget deficit below 3% by the end of 2014.

The new laws will entail cuts to pension benefits, introduce severe penalties for early retirement, increase the retirement age and change the formula for the calculation of pensions.

The effective average retirement age will increase from 61.5 years to approximately 63.5 years.

The statutory retirement age is currently 65 years for men and 60 for women working in the public sector.

However, some public and private-sector employees - such as the police, dock workers, security services and journalists for public TV and radio - can retire in their 50s because they are entitled to a pension after 35 years of social security contributions.

In future, the minimum number of years someone will have to work to qualify for a full pension will rise to 37, and there will be strong incentives to stay in the working life for 40 years.

The legislation was met with protests from the country's two major unions, causing local airlines to cancel and reschedule flights, paralysing public transport in Athens and disrupting ferry traffic between the mainland and the islands.

Many in Greece, however, are starting to support the austerity measures.

A poll by To Vima, one of the leading dailies, showed nearly 45% of respondents thought the protests would make things worse.

More than 20% thought the protests were justified, but harmed the economy, while 31% said they were necessary to prevent social security reform.