The prime minister of Hungary, Viktor Orbán, has ramped up his populist rhetoric ahead of April elections to claim that “dark clouds are gathering” and that his country is a last bastion in the fight against the “Islamisation” of Europe.

In his annual state of the nation speech, Orbán, who already appears set to win a third consecutive four-year term, made what are now familiar claims about his success in beating back threats to Hungary’s way of life from “Brussels, Berlin and Paris politicians”.

“We sent the muzzle back to Brussels and the leash back to the IMF,” he said early in his address on Sunday, praising the strength of the country’s economy.

The part of his speech which inevitably alighted on the threat of immigration will particularly concern Orbán’s many critics home and abroad.

He claimed the west had “opened the way for the decline of Christian culture and … Islamic expansion” while his administration had “prevented the Islamic world from flooding us from the south”.

Deploying a host of questionable statistics and apocalyptic visions, Orbán said: “We are those who think that Europe’s last hope is Christianity … If hundreds of millions of young people are allowed to move north, there will be enormous pressure on Europe. If all this continues, in the big cities of Europe there will be a Muslim majority.”

He said immigration was no more helpful for a country’s national development than influenza contributed to a human body’s health.

The rhetoric will strengthen the hand of those calling for Orbán’s rightwing populist party Fidesz to be ousted from the transnational European People’s party, of which Angela Merkel’s CDU is a member.

Orbán’s personal bete noire, the Hungarian-American financier and philanthropist George Soros, was also once again a target.

He accused Soros of having used his fortune not only to buy influence in Brussels and the west, but also at the UN. Further unspecified measures were floated as a response, building on legislation designed to crack down on foreign-funded organisations.

There was a conspiracy to create a “Homo sorosensus, the Soros type of man” that must be a rejected, he said.

“Hungary is not a country of troubled people, we understand that György Soros’s men were already in the UN,” Orbán told his audience at the Várkert Bazár, a restored neo-Renaissance building on the Danube, outside which hundreds of people protested.

Orbán pledged his government’s solidarity with “those western European people and leaders who want to save their country and their Christian culture”.

“We are waiting for the Italian elections, where Silvio Berlusconi can again occupy the government positions.”

Gyula Molnár, the president of the socialist MSZP, said of the speech: “It was the product of a medium-sized enterprise manager with some fake illusions.”

Fidesz has the support of more than 40% of decided voters in a country where the media is largely pliant and the opposition divided.