LISBON, Jan. 24 (Xinhua) -- Portuguese Prime Minister Antonio Costa defended the need for EU reform on Tuesday to fight against protectionism and populism.

"Building the euro is building Europe and defending the euro is defending Europe, defending a Union that has guaranteed peace and prosperity between European countries for 60 years," Costa said during a seminar at the Calouste Gulbenkian Foundation in Lisbon.

The conference held in Lisbon, entitled "Consolidating the Euro. Promoting convergence," took place on the same day when the Supreme Court in Britain ruled that the British prime minister could not start the process of leaving the EU without first gaining approval from the British Parliament.

Costa pointed to the dangers of a rise of inequality in Europe and ruled out the idea that the reform of the euro zone would lead to less discipline or more exceptions between member states.

Measures he mentioned to reform the euro zone include ensuring "the European Stability Mechanism evolves in the direction of the European Monetary Fund" to deal with sovereign debt.

He argued that the euro is one of the main achievements of the process of the European construction.

"Pro-European leaders cannot be paralysed before the rise of nationalism, protectionism, populism and xenophobia," he pointed out. "The EU needs a new virtuous cycle of growth and convergence. Europe can only face current challenges if it is united."

He also said that the need to reform the euro should not lead to division or confrontation between member states.