Downing Street has said it “expects” that university students will be able to go home for Christmas despite coronavirus outbreaks on campuses.

It marks an apparent relaxing of the government’s position after culture secretary Oliver Dowden could only say he wanted students to be able to return home if Britons follow Covid-19 restrictions and get the virus under control.

“We would expect all students to be able to go home at Christmas,” Boris Johnson’s official spokesperson told reporters on Monday.

The prime minister is facing pressure to address the situation in universities after warnings from the National Union of Students (NUS) that people are being “trapped” in their halls of residence in “disgusting conditions” due to self-isolation rules.

Thousands of students are self-isolating following a surge in cases at universities including Glasgow, Manchester Metropolitan and Edinburgh Napier.

Students at Manchester Metropolitan on Sunday claimed they were being falsely imprisoned, with a number of legal experts backing them on social media.

The university later said it could not stop students under Covid-19 lockdown leaving their accommodation, but that it expected them to follow self-isolation guidance.

NUS president Larissa Kennedy told Good Morning Britain: “I’m hearing from some students across the country where there are security guards outside of these blocks where students are being kept, stopping people from leaving, coming and going, where students are being discouraged from getting deliveries and told by the university that they’ll deliver food, and that delivery has not arrived, and so they’ve gone for the day without food.

“I’ve heard from other students who, they’ve turned up with an amount of toilet roll, told with no notice that they’re going to be locked down and wondering where the next roll of toilet roll is coming from.

“It just feels like these are disgusting conditions for students to have been trapped in.”

She said people should follow public health guidance but questioned the legality of keeping students “cooped up in that way without that access to the things that they need”.

Asked if universities have the power to lock students in halls, the PM’s spokesperson said: “The laws for students are the same for the rest of the public.

“Universities can issue advice to their students and I believe that’s what’s been happening in recent days.

“Students follow the same rules as other people living locally and therefore would be subject to the same rules in relation to localised lockdowns.”

Nicola Dandridge, chief executive of the Office for Students (OfS), the higher education regulator in England, said it would be “looking very closely” at the quality of education being provided by institutions.

Speaking to BBC Radio 4’s Today programme, she said institutions must be clear with students on what teaching conditions they can expect and if this changed.

“What we can’t have is a situation where students don’t know what’s going on, that they’re locked in their halls of accommodation, and can’t get hold of food,” she said.

She said students had “legal rights as consumers” and could raise complaints with their university and the Office of the Independent Adjudicator.

Asked if students should receive a refund of tuition fees she said it was “a question for government”.

But Johnson’s spokesperson said: “Universities are autonomous and they set their own fees.

“What we would expect is that they continue to deliver a high quality curriculum to their students.”

Meanwhile, the University and College Union urged the PM to ensure online tuition at universities “becomes the norm”.

In a letter to Johnson, it accused accused some institutions of adopting a “stubborn position” over requiring in-person teaching because they depended on rent from student accommodation.