Forcing students to stay “cooped up” in their halls over Christmas if there are coronavirus outbreaks is “impractical” and could lead to mental health problems, a university vice-chancellor has said.

A Government scientific adviser has suggested that students may have to stay in their university accommodation when term ends to ensure the infection does not spread to their older relatives.

But Professor Colin Riordan, president and vice-chancellor at Cardiff University, has warned that it would be “extremely difficult” to handle the situation and would cause “an awful lot of stress”.

His comments come after Sir Mark Walport, a member of the Scientific Advisory Group for Emergencies (Sage), said students may have to remain at university if they become infected at the end of term to prevent them from spreading the infection to other parts of the country and other communities.

It's impractical to say to students they need to stay over Christmas if they don't want to

Prof Riordan told the PA news agency: “I feel it’s impractical to say to students they need to stay over Christmas if they don’t want to. I don’t know how we would enforce that, or where we get the authority to do that, so that would have to be a matter for Welsh Government.”

Health Secretary Matt Hancock has not ruled out the prospect of asking students to stay on campus over Christmas amid coronavirus clusters in university halls.

Prof Riordan added: “I really personally hope that we don’t end up in that situation because it would be extremely difficult to handle.

“It would cause an awful lot of stress and you know there’s a potential for mental health problems telling people they have got to be cooped up in their student room over Christmas.”

On Friday – just days before the start of term at Cardiff University – Wales’s health minister announced that Cardiff will become the first capital city in the UK to be placed under a local lockdown from 6pm on Sunday.

Vaughan Gething said restrictions will also come into force for Swansea at the same point while the town of Llanelli will be placed under lockdown a day earlier at 6pm on Saturday.

But students will be able to travel into Cardiff and Swansea to attend university, the minister confirmed.

Mr Gething said it would be “an interruption” in the normal university experience, where people would expect to go out and want to meet many other people.

Speaking just hours before the lockdown was announced, Prof Riordan told PA that the university was “stepping up security patrols” around campus halls throughout the night-time to ensure students stick to rules.

Students could face a range of penalties – including suspension or expulsion – if they repeatedly flout the regulations, the university leader warned.

In the event of an outbreak on campus during term-time, Prof Riordan suggested Cardiff students could be asked to self-isolate in residential blocks to ensure they can still carry on their learning remotely.

But he said he was hopeful that their testing centre on campus – for staff and students who are asymptomatic – could act as an “early warning” system to prevent the virus from spreading further.

His comments come as freshers in Scotland have been told not to go to bars and restaurants as hundreds of students have been forced to self-isolate at halls of residence after Covid-19 outbreaks.

But Nicola Sturgeon has insisted students are not to blame for a rise in coronavirus outbreaks.

The First Minister said universities are responsible for supporting students’ mental health during outbreaks in student accommodation and have a “big, big responsibility” to look out for their welfare.

Ms Sturgeon said the Scottish Government is assessing whether self-isolating students can be allowed to return to their family homes, and guidance on that could be issued over the weekend.

It is unjust for students to have to adhere to different rules from the rest of the population, and this will only make the guidance even more confusing and harder to follow

Larissa Kennedy, president of the National Union of Students (NUS), said: “We must not demonise students for the failures of Government.

“Students have done everything they have been asked to do during this pandemic, and are now returning to university campuses in accordance with Government advice.

“It is the Government who now need to put an effective strategy in place to keep Covid-19 under control through mass testing and clear guidance for all students.”

She added: “It is unjust for students to have to adhere to different rules from the rest of the population, and this will only make the guidance even more confusing and harder to follow.

“Students and young people should not be scapegoated for any outbreaks of coronavirus that they are not responsible for. Not only would this be inaccurate and unfair, it would also create a culture of mistrust that we know would not be beneficial in keeping everyone safe.”

Following the announcement of a local lockdown, a Cardiff University spokeswoman said the institution will continue to provide face-to-face teaching next week “as part of a blended learning provision”.