A Polish court has sentenced a former chemistry professor to 13 years in prison over a plot to blow up parliament using a car loaded with tonnes of explosives.

Brunon Kwiecien, 48, was convicted of planning to assassinate the president, prime minister and members of parliament in 2012.

The former professor at Krakow's University of Agriculture in southern Poland is said to have been fascinated with Norwegian mass murderer Anders Behring Breivik.

Kwiecien had hidden four tonnes of explosives in a car which he planned to use during a parliamentary debate that President Bronislaw Komorowski was due to attend.

"If Brunon Kwiecien hadn't been stopped, we would be talking amid the ruins of the state today," said judge Aleksandra Almert, delivering the verdict in the District Court in Krakow.

"All steps taken by Brunon Kwiecien related to the attack on parliament were driven by his wish to lead a revolution, to kill the president, cabinet ministers and lawmakers."

Donald Tusk, then prime minister and now EU chief, said at the time that Kwiecien "did not conceal his fascination with Breivik", the right-wing extremist who killed 77 people in a bombing and shooting rampage in Norway in July, 2011.

Wife's tip-off likely reason terror plot was uncovered

Kwiecien, a nationalist without any obvious links to political groups or extremists, was arrested in November 2012 after what the media said was a tip-off by his wife.

He was found with a stockpile of TNT, gunpowder and other explosives as well as firearms, military helmets, bullet proof vests and fake drivers' licences.

Throughout the hearing, Kwiecien insisted he had fallen victim to "provocation" by Polish intelligence agents who had forced him to act.

But Kwiecien, who has the right to appeal against the verdict, never denied planning the attack, for which he tried to recruit two of his students.

"We cannot speak about provocation. It's enough to hear the accused and collect evidence. He was the mastermind behind every element of the attack," Judge Almert said.

AFP