In desperation Keith Murdiff texted his boss on Christmas Eve one year to ask when he would be paid.

The English teacher had two children at the time (a third has since been born) and did not know if he had money to buy presents.

“I felt embarrassed and ashamed, because I couldn’t tell my wife, ‘Yes, we can buy this present or that present for the children’,” he says. “I had no idea.”

When he went back to his language school in Dublin after the holidays he was taken into a room and was given a “dressing down” for texting a manager the day before Christmas.

“I was given a verbal warning,” he says.

Murdiff (42) says his experience is widespread in the teaching English to international students industry, worth an estimated €762 million to the Irish economy.

He has worked in more than a dozen schools in Dublin over the past 15 years.

“In all those jobs I wanted a contract, I wanted to be permanent, but that choice wasn’t open to me,” he says.

“A lot of the schools I worked in I would have had no contract at all – just arranged my hours orally. I might get a contract if there was a Department of Education inspection looming. But they would have no specified hours.

“I’ve never had sick pay, never had holiday pay, never had a salary. I’ve only ever been paid by the hour. But not by choice.”

The married father of three children, whose children are now aged eight, six and one, said he could never get a mortgage because of his precarious employment. He still rents.

Bills went unpaid when he did not get paid. Other times, he would have to urgently reassess his outgoings when he was told halfway through the month that his hours were switching to part-time for a few weeks.

“There was no consistency whatsoever,” he says. “It got to the stage where it stressed me out so much, it affected my relationship with my wife, it affected my relationships with with my friends – I didn’t want to see my friends because I was so ashamed and so embarrassed.”

Murdiff ended up in counselling for stress management.

Since then he has taken up his first permanent job as an organiser for the trade union Unite, as a result of representing his teaching colleagues.