The march in Lisbon was one of the biggest in Portugal for years [Reuters]

EU leaders have begun a summit in Portugal that is aiming to put aside recent national differences over a proposed EU constitution and unite around a new treaty.

However the start of the gathering was overshadowed by what is believed to be Portugal's biggest demonstration in 20 years and by renewed political disagreements over the treaty.

Organisers estimated as many as 200,000 people gathered near the venue of the EU conference in the Portuguese capital on Thursday to oppose so-called "flexicurity" changes to labour laws which are being considered during the summit.

Flexicurity aims to combine flexible work laws with higher social protection for the unemployed.

"Flexicurity is, above all, for this government, a slogan to impose liberalisation and a lack of job protection for many years," Jose Carvalho da Silva of Portugal’s largest union, the CGTP, said in a speech at the rally.

The government of Jose Socrates, the Portuguese prime minister, has introduced tough spending cuts and reduced civil servants' benefits since coming to power in 2005 with an aim to ensuring that Portugal meets EU budget deficit goals.

It is also pushing for changes to the country's labour laws.

Voting wrangle

The demonstration came as EU leaders arrived in Portugal to seek an end to a political impasse that began when Dutch and French voters rejected a proposed EU constitution in referenda in 2005.

The new EU treaty provides a new decision-making system and more say for the European and national parliaments but omits mention of an EU constitution, anthem or flag.

Poland fought against the changed voting system at a summit in June and has recently voiced greater optimism that it would win a compromise on its demands.

"We don't want anything more than is our right," Lech Kaczynski, the Polish president told national radio before leaving for the summit.

Brown says he will not return to
Portugal if Mugabe is going to be there [AFP]

Asked what would happen if Polish demands were not met, Kaczynski replied: "We will have to delay the discussion".

But Socrates, who is chairing the two-day summit, said he was very confident of a deal this week as did the German chancellor Angela Merkel who has led efforts to win over the Poles.

Other attendees in Lisbon include Nicolas Sarkozy, the French president, who arrived in the Portuguese capital just hours after it was announced he is to separate from his wife Cecilia.

Gordon Brown is attending his first EU summit as the British prime minister and used the opportunity to warn that he may not return to Portugal for a planned EU-Africa summit later in the year if it is confirmed that Robert Mugabe, the Zimbabwean president, is to be there.

"We will not participate in a conference that President Mugabe is at. We cannot sit down at the same table as President Mugabe," he  said

The summit due to be held in December is to be discussed at the sidelines of the current gathering and Luis Amato, the Portuguese foreign minister, said last week the guest list would be finalised by the end of October.

Source: Agencies