Kuwait is planning to launch its biggest-ever crackdown on illegal residents in an operation that is expected to see more than 100,000 arrested, according to an interior ministry official.

The operation will be targeting foreign workers that have violated the terms of their visa or let them expire, Major General Sheikh Mazen Al-Jarrah, Interior Ministry Assistant Undersecretary for National and Passport Affairs told Kuwait Times.

He did not give details of when the plan would be implemented.

The announcement comes after a similar crackdown in June 2013 that saw more than three thousand illegal workers deported.

Around 70 per cent of Kuwait’s 3.37 million population is made up of foreign workers.

The high level of immigrants is a source of tension and led to the 2013 announcement that 100,000 foreign workers would be deported every year for ten years.

Engineering, procurement and construction (EPC) contractors fear that Kuwait’s anxiety about the size of its expat population could cause problems as the country ramps up construction activity.

Record oil and gas contract awards are expected in Kuwait over 2015, driven by the $14bn Al-Zour New Refinery Project.

It is expected that five New Refinery Project packages worth a total of $11.5bn will be awarded over the year.

“With the huge number of projects gearing up in Kuwait, hostility to an increase in the number of foreign workers is a real cause for concern,” said an official for an EPC contractor who asked to remain anonymous because he is not authorised to speak to the media.

“Hundreds of thousands of extra workers are going to be needed to carry out the country’s large infrastructure projects and importing labour already involves too much red tape.”

Workers from India make up Kuwait’s largest expat population, with 545,000 living in the country.