Portugal is in the midst of a constitutional crisis after President Anibal Cavaco Silva refused to allow a coalition of left-wing anti-austerity parties to take power even though they have a majority in parliament.

The centre-right party of Prime Minister Pedro Passos Coelho will instead be allowed to continue in power to satisfy the desires of Brussels, despite falling well short of a majority in elections earlier this month. Its ability to govern is in question, however, with the left easily able to vote down government legislation.

Antonio Costa, the radical leader of the Socialist Party, branded the President’s actions a “grave mistake” and accused him of trying to steal power from parliament.

“It is unacceptable to usurp the exclusive powers of parliament. The Socialists will not take lessons from professor Cavaco Silva on the defence of our democracy,” he said.

He vowed to go ahead in forming a coalition with the Left Bloc and the Communists, and immediately subject the government to a vote of no confidence.

Should Portugal allow the anti-Euro Left wing parties to form a government? — Raheem Kassam (@RaheemKassam) October 24, 2015

However President Silva defended his decision, saying it was too risky to let Eurosceptic parties take power.

“In 40 years of democracy, no government in Portugal has ever depended on the support of anti-European forces, that is to say forces that campaigned to abrogate the Lisbon Treaty, the Fiscal Compact, the Growth and Stability Pact, as well as to dismantle monetary union and take Portugal out of the euro, in addition to wanting the dissolution of NATO,” he said.

“This is the worst moment for a radical change to the foundations of our democracy.

“After we carried out an onerous programme of financial assistance, entailing heavy sacrifices, it is my duty, within my constitutional powers, to do everything possible to prevent false signals being sent to financial institutions, investors and markets.”

He also tried to justify his decision by saying the majority of Portuguese people did not vote for parties that want to leave the euro, as the Left Alliance and Communists do.

Green MEP Rui Taveres said: “The president has created a constitutional crisis. He is saying that he will never allow the formation of a government containing Leftists and Communists. People are amazed by what has happened.”

Portugal went to the polls three weeks ago in an election that saw a major set-back for the governing centre-right. Nonetheless, they remained the largest party and so got first shot at forming a new government, but have found no coalition partners.

The IMF says Portugal remains “highly vulnerable” after leaving a Troika-imposed austerity regime, and warns that it could slide back into crisis if it fails to deliver on reforms, the Telegraph reports.

Its public debt stands at 127 per cent of GDP, and total debt is 370 per cent, which is even worse than Greece.

Under the Greek constitution, new elections cannot be held until next year, leaving the possibility of nearly a year of uncertainty.