Hundreds of EU nationals have been told they don’t have the right to stay in the UK after applying for post-Brexit immigration status, figures show.

The latest statistics on the government’s EU settlement scheme, published on Thursday, show 300 people have been refused settled status. These individuals will not have a right to live in Britain after the deadline of June 2021, unless they successfully appeal the decision.

The number remains proportionately small, as there have been nearly 3 million applications processed overall, but it marks a considerable jump from the previous monthly figures, when just seven people had been refused.

At that point the refusals were all on the grounds of criminality, but most of the latest refusals were due to issues around eligibility – usually because the applicant has been unable to provide the relevant documentary evidence.

While the number is still proportionately low, campaigners have raised alarm at the sudden increase, and it is likely to prompt concern around difficulties more vulnerable people face when obtaining evidence.

The Home Office said officials had made every attempt to obtain the necessary evidence before refusing applications, and that decisions to refuse were not taken lightly and signed off at a high level.

Maike Bohn, co-founder of campaign group the3million, told The Independent she was concerned by the fact that while there had been no refusals on eligibility grounds before February 2020, there was now a sharp rise.

“This is hard to explain. We urgently need more explanation from the Home Office as to why those cases have been refused,” she said. “It is concerning that as soon as the UK left the EU we see people being refused settled status.”

Christopher Desira, immigration solicitor at Seraphus law firm, said there were likely to be more and more refusals beyond criminality grounds, which may worry a lot of people in uncommon family arrangements, which tend to be the most complex applications.

He also raised alarm over the gaps in free outreach and advice services that are likely to form due to the coronavirus outbreak, which may cause problems for those receiving requests for further information from the Home Office, but not know how to respond, and called on the Home Office to pause any refusals until the emergency is over.

Liberal Democrat home affairs spokesperson Christine Jardine called on the government to back the Private Members’ Bill she tabled last month that would guarantee the rights of EU citizens in the UK.

She said: “EU citizens in the UK have been living under a cloud of uncertainty for far too long. They are our families and friends, our colleagues and carers. They must have the right to stay. Even before the coronavirus crisis, we were warning that tens of thousands of EU citizens will be left without settled status when the Conservative government’s arbitrary deadline hits next year.

“That would leave thousands of people effectively undocumented and at risk of eviction, detention and even deportation. It will be a new Windrush scandal on an even bigger scale.”

The Home Office figures show that overall, there have been more than 3.34 million applications to the scheme up to the end of February 2020.

Minister for future borders and immigration Kevin Foster said: “EU citizens have made huge contributions to our country. It’s good news over three million have now been granted status and will be able to continue to call the UK home for decades to come.”

The department said it had a wide range of support was available online, over the phone and in person to help EU citizens apply for settled status.

Earlier this month, the department announced a further £8m of funding to award 57 charities to help vulnerable EU citizens apply, on top of £9m announced for the same cause last April.