Academic staff at the two universities in Brighton are to strike for 14 days in a dispute over pay and conditions.
The strikes at Sussex University and Brighton University are due to start on Thursday (20 February) and culminate in a week-long walkout ending on Friday 13 March.
In addition, teaching staff at Sussex are also embroiled in a dispute over pensions, with staff expected to pay in higher contributions while working and receive less when they retire.
Students at Sussex have been told that they can apply for an “ex gratia” payment of up to £100 for any distress and inconvenience caused by the strikes.
Sussex is believed to be the only university in the country offering payments to students, with domestic undergraduates currently paying £9,250 a year in tuition fees.
It said: “The University of Sussex believes this is important to offer its students.
“The university has considered guidance from the Office of the Independent Adjudicator for Higher Education, the independent body set up to review student complaints.”
The latest walkout has been called by the University and College Union (UCU) and follows eight days of strikes in November and December as part of the same dispute.
Sussex and Brighton are among 74 universities affected by strike action – up from 60 before Christmas.
Students at Sussex were told that UCU members made up about 30 per cent of the university’s overall workforce.
The university said: “The majority are academic staff. Some teaching, but not all, is anticipated to be disrupted.
“Some staff may choose to let their students know in advance if they are not going to teach a class although they are not legally obliged to do so.”
The UCU said that the walkouts starting on Thursday would be “the largest wave of strikes ever seen on UK campuses – the number of strike days is unprecedented”.
Members are due to take action on Thursday and Friday this week and on Monday, Tuesday and Wednesday next week.
Further strikes are scheduled from Monday 2 March to Thursday 5 March and from Monday 9 March to Friday 13 March.
The union added: “At the University of Brighton, staff will be on picket lines from 8am each day at the Falmer campus, the Moulsecoomb campus and the Grand Parade buildings in the city centre.
“At the University of Sussex, staff will be joined by colleagues from the Institute of Development Studies on picket lines at Falmer House in Gardner Centre Road from 8am each day.”
UCU regional official Mike Moran said: “It is incredibly frustrating that UCU members are being forced to walk out again to secure fair pay, conditions and pensions.
“This unprecedented level of action shows just how angry staff are at their universities’ refusal to negotiate properly with us.
“If universities want to avoid continued disruption then they need to get their representatives back to the negotiating table with serious options to resolve these disputes.”
The UCU said that members at Sussex were walking out over both the pensions and pay and conditions disputes.
Staff at Brighton were walking out over the pay and conditions dispute only while UCU members at the Institute of Development Studies were striking over the pension changes.
The union added: “UCU members at all three institutions were among staff at 60 universities who walked out for eight days of strikes before Christmas.”