University workers have formed picket lines on campuses across the UK on the first day of the “biggest-ever wave of strikes” over higher education pay, pensions and working conditions.

The University and College Union (UCU) reported that support from staff and students remained solid, despite the fact it will be the third time university staff have gone on strike in the last three years – most recently just before Christmas.

UCU branches across the country posted pictures of lively picket lines at universities in Manchester, Glasgow, Sheffield, Essex, Newcastle and Cardiff among others, and there were messages of solidarity from politicians including the Labour leadership contender Rebecca Long-Bailey.

Angela Rayner, the shadow education secretary, said: “Labour stands in solidarity with striking university workers today. They are on strike due to the failed marketised system created under the Tories.

“They don’t do so lightly. Reasonable terms and conditions and fair pensions are the minimum they should expect, and their treatment is a stark contrast to the eye-watering pay packets of a few vice-chancellors.”

Up to 50,000 lecturers, technicians, librarians and other academic and support staff at 74 universities will take part in a total of 14 days of strike action, staggered through February and March, which will potentially affect about 1.2 million students through lost lectures and tutorials. Many have expressed their support for staff, but are pushing for compensation from university managers.

Trespassers no more! Thank you to all of our amazing members and supporters who joined us on the @uobgreenheart today. We hope our strike chants were heard by @unibirmingham management! ✊ #UoBStrike #UCUStrike #UCUStrikesBack pic.twitter.com/yLEpqDfXsm — Birmingham UCU is preparing to strike back (@BirminghamUCU) February 20, 2020

In south London, students sipping cups of “solidaritea” joined staff at Goldsmiths University of London on picket lines outside the Richard Hoggart building. “The workload is simply becoming unsustainable for many in the profession,” said Philippa Burt, a theatre and performance lecturer.

Wearing a high-vis vest and brandishing leaflets, Burt said that while there were specific demands from the UCU, many had joined the picket lines because of concern about a general decline in working conditions. She said her timetable, under which she works six days a week but is only paid for four and a half, is typical across the profession.

Goldsmiths staff on strike. Photograph: Georgie Hodges

“We’ve seen pay cuts alongside an exponential growth in workload,” added another senior lecturer, who did not want to be named.

Many of those on the Goldsmiths picket said the current strike, which follows an eight-day walkout shortly before Christmas, was the result of universities refusing to negotiate with the UCU. Employers, however, insist they have gone a long way to meet union demands.

The Universities and Colleges Employers Association (UCEA) said on Thursday that disruption for students would be limited. They claimed that during the pre-Christmas strikes 29% of UCU members took strike action at affected universities, representing just 5% of all staff, and that early reports from this latest action suggested turnout had fallen further.

A UCEA spokesperson said: “It will take time for universities to find out exactly how many scheduled classes have not taken place on a given day. Feedback also points to mixed support and impact across the minority of UK universities affected by the strikes, and each university is of course focused on managing this period of disruption as best they can for their students.”

One lecturer at Goldsmiths said: “They’ve consistently reneged on their promises and have failed to consult us every step of the way. And we’ll be here again in a few months if we have to be.”

A theatre lecturer on the picket line, who did not want to be identified, disputed the employers’ claim earlier this week that pay increases and better working patterns were not financially viable. “The money always seems to be there for capital investment but never for the wellbeing of staff or students.”

A fine-art lecturer with 15 years’ experience said she initially supported the protests in December because of the proposed increase in pensions contributions by staff, but that recent cuts and a reorganisation of her department had attracted others to the cause.

“This is part of a wider move towards marketisation of higher education,” she said. “They’re taking away our autonomy and the result is that we’re working longer hours for less.”

Zoe Sanders, a student in the art department, gave the lecturers her full backing. “Their demands for better working conditions are also demands for better learning conditions.”

The UCU is calling on university managers to address excessive workload, pay, a 15% gender pay gap, increased casualisation and changes to pensions for staff in the Universities Superannuation Scheme (USS). Members are being asked to pay 9.6% in pension contributions, up from 8%, and the UCU wants universities to pay the full increase instead.

The UCU general secretary, Jo Grady, said: “We have been receiving news of solid support for the strikes across the UK. That support sends a clear message to universities that, instead of focusing on silly games and spinning in the run up to the walkouts, they should have been working with us to try and sort things out.

“We have been clear that we are always ready to seriously discuss all the issues at the heart of the disputes. Students are understandably unimpressed at the intransigence of their university leaders and have made clear demands today that vice-chancellors and principals work harder to try and resolve the disputes.”

However, UCEA said the demand for a pay rise of more than 5% was unaffordable, with several universities reporting deficits in their latest accounts. “UCEA has consulted all of its members in presenting new positive proposals addressing the important issues around employment in universities, focusing on casual employment, workload/mental health and gender pay gap/ethnicity pay. UCU is urged to consult all of its members, including the vast majority not taking strike action, and present these positive proposals to them.”