The action comes after police raided the offices of leading construction unions in the capital, Seoul, in January. Union officials were suspected of coercing employers into hiring union members and demanding bribes from those who refused.

There are now allegations of widespread violence breaking out on sites across the country.

Yoon said that eradication of illegal activities on Korean building sites was a key part of his government’s programme of labour reforms.

The government has set up a dedicated team at the Land Ministry and launched a 200-day crackdown by the National Police Agency, reported The Korean Herald newspaper.

Korea now has a special name – “keonpok” – to describe ‘construction violence’. The term was coined during a press briefing about the problem, according to the Herald. The word is a modification of “jopok”, which refers to organised crime.

A government official told members of the press that “Like organised violence or school violence, some strong union members systematically commit illegal acts at construction sites, causing enormous damage to companies and the national economy”.

The briefing took place immediately after a cabinet meeting attended by the ministers of land and justice and the head of the national police agency.

Land minister Won Hee-ryong reportedly outlined a plan to suspend licenses if certain construction personnel – such as tower crane operators – attempted to force construction companies to pay a monthly fee “as a sort of bribery”.