Academic and student leaders today claimed to have "crippled" universities across the country, bringing campuses to a standstill in protest over top-up fees and low pay.
However, the university employers claimed that a "straw poll" they had carried out today indicated that the impact had been "minimal", with 56% of targeted campuses reporting no noticeable impact.
The Association of University Teachers (AUT) released a statement claiming that the universities of Leeds, Glasgow, Liverpool, Sussex and University College London, among others, had been "all but shut down" with no lectures taking place.
Leeds University confirmed that the shut-down was "pretty comprehensive", however lectures were known to be taking place at University College London.
The president of the National Union of Students (NUS), Mandy Telford, said that up to two million further and higher education students had opted out of classes today to protest over the government's plans for top-up fees.
She said: "Students have turned out in record numbers and joined lecturers in protest at government proposals to introduce fees. There is now an increasing number of universities, academics, students and the general public who are vehemently opposed to future students being charged up to £3,000 to study at university."
The AUT, which is striking this week over a new pay deal which they say will leave some of their members worse off, claimed the action was unprecedented. The general secretary, Sally Hunt, said: "The way in which our members have crippled the UK higher education system is symptomatic of the extreme anger felt by staff over the issue of pay and conditions."
Ms Hunt also vowed that the AUT would continue its action with a boycott of this summer's exams, which could mean that some students would be unable to graduate this year.
When lecturers were balloted for the action earlier this month, 54.4% of those who voted backed strike action, and more that eight out of 10 lecturers were behind the second option of industrial action short of a strike.
Today, a University Council for Educational Administration (UECA) poll found that 16% of universities had reported significant impact, mainly affecting certain parts of the institution.
In 53 of the 166 higher education institutions in the UK staff were not balloted, meaning that there is no AUT strike action. However the NUS strike was affecting all universities.
Jocelyn Prudence, the chief executive of UCEA said: "We are glad to see that education is carrying on as normal in most institutions, but feel for those students whose education has been disrupted by this unnecessary and regrettable action.
"We remain convinced that the way to resolve this dispute is not through strikes and other disruptive action, but by constructive dialogue.
"The impact of this action was always going to be patchy, with 53 of the 166 institutions in the sector not being balloted for strike action, and another 40 with only minimal AUT membership."
Reports from around the country
Aberdeen University
David Donaldson, the vice-president of the Aberdeen Students' Union said: "The campus is pretty quiet although the five inches of snow are adding to that... Many of the classes have been cancelled, though the majority of lecturers told the students in advance. The students are actually fairly supportive of the lecturers."
Birmingham University
A spokesperson for the university said: "There is a very small number picketing, I counted 11 this morning. There are a thousand AUT members at Birmingham, and only half voted to strike."
The president of the student union, Kirsten Jonberg, said: "We are calling for a student strike and are working with the AUT to cover all entrances to the university. We're also giving out flyers and stickers to students if they choose to go into lectures. Obviously not everyone is choosing to strike because of exams and dissertations."
"Lots of lectures have been cancelled - everyone has had at least one lecture cancelled."
Edinburgh University
A spokesperson said: "There's not a great level of disruption on campus."
Will Garton, the president of the Edinburgh Students' Union, said: "Both staff and students are on the picket lines."
"We don't have any members of the NUS, though our students are joining the AUT members in their protests."
"We realise that there are some short-term losses for the students missing lectures but we must look at long-term impact which is more significant."
Leeds University
A spokesperson said they were waiting for full reports of activities but admitted that the shut-down was "pretty comprehensive".
Plymouth University
David Clark, the student union welfare officer, said: "Today we did strike across campus. We had 100 on the picket lines with people shouting and chanting."
"It's been fantastic. Traditionally we have worked closely with lecturers as we believe our causes lay hand in hand".
University of East London
Some students are striking but the university doesn't have AUT members, so lecturers are all at work.
John Pierce, of the UEL student union, said: "There is a picket of 70-100 people as you go in, but lectures are still running as normal.
"Word of mouth has increased awareness, it's not just the Students Union telling their friends it's important, it's their friends telling them in bars and stuff."
University College London
NUS and AUT on campus claim that despite high numbers of overseas students every department has cancelled some lectures. Computing services closed and libraries operating limited services.
South Bank University
A spokesperson for the university said: "As far as I know nothing is taking place."
"Everything here is calm, relaxed and going as normal. There is no action taking place as far as I know of."
