Manuel Murillo Sanchez, a 65-year-old security guard from the north-eastern city of Terrassa, was arrested in September 2018 after police were alerted to messages he shared with a right-wing WhatsApp group.

He told members of the group he was furious at the prime minister’s plans to exhume late dictator Francisco Franco from his high-profile resting place near Madrid, an operation that finally took place in October 2019.

“We can’t let them humiliate the generalissimo,” he wrote in one message according to the National Court ruling.

“If it is needed I will go armed and will sit on Franco’s tomb and if they come near I will shoot.”

Murillo Sanchez expressed on several occasions his intention to “end” the premier’s life to “produce a change in Spain’s political situation”, and requested help from members of the group to carry out his plan, the ruling said.

While the man did not have “a definitively concocted plan”, the court said it took into consideration the danger represented by his “determination” and the weapons found in his house.

The court found him guilty of unlawful possession of weapons and explosives and plotting to commit murder and sentenced him to 7.5 years in prison, said the ruling.

When he was arrested, police found several weapons and ammunition, including a handmade crossbow, at his home, the court said.

The court also banned him from owning weapons for eight years.

It rejected his argument that he had been under the influence of alcohol and tranquilisers when he made his threats against the prime minister.

The Spanish government said at the time of his arrest that the prime minister’s security “had never been compromised”.