More than 500 employees, inclusing cleaners, security workers and administrative staff, are taking part in five days of action from today and ending on Friday, June 24.
Employees are angry that despite rejecting the 1.5 per cent pay offer made last August, while Unison claims managers "ignored staff protests and imposed the increase".
But the University of Leeds claims its lowest paid workers will receive an uplift of "up to nine per cent" in the coming year, as well as one-off payments of £650 to every member of staff up to grade six next month.
The union claims that, even with this increase, low-paid employees are still taking home less than £18,000-a-year.
Workers want an across-the-board £1,250 increase to help them cope with soaring prices and inflation.
Now with prices rocketing, they cannot afford to accept a pay offer that's already been wiped out by inflation, the union adds.
UNISON head of education Mike Short said: “Striking is always the last option, but staff have been left with no other choice.
“For years, university workers have endured what amount to pay cuts. Yet, these are the people who made sure students’ learning was uninterrupted throughout the pandemic
“But enough’s enough. University employees simply can’t afford to live on poverty wages or accept woeful, insulting pay offers.
“University managers must make a better offer to give a fair pay increase to all staff.”
A University of Leeds spokesperson said: “We recognise these are difficult times for many of our staff and students, as they are for much of society, and we are taking positive action.
"Even before the rise in global cost of living pressures, the University was working constructively with our trades unions to improve employment terms and support our lowest paid staff. This includes moving many staff from fixed-term to permanent contracts, reviewing how we employ hourly paid and casual staff, and continuing to meet the voluntary living wage.
“At a national level, the sector’s nationally negotiated pay offer provides for a far greater uplift for staff on the lowest pay scales – up to nine per cent in the coming year.
“While the University cannot support the industrial action, we know that our colleagues are uniformly committed to our students’ education and experience, and do not enter into any such action lightly."
It added a one-off payment of £650 will be made in July to all staff in roles up to and including grade six. This will be in addition to the 2022/23 nationally agreed pay award.