The Home Office has issued 59 pages of guidance notes to help staff register EU citizens for a post-Brexit scheme that the former home secretary Amber Rudd said would be as easy to apply for as an online account with the clothes retailer LK Bennett.

But case workers will have to read through to page 56 to discover that they should not apply the government’s hostile environment policy in their assessments.

When the government unveiled details of the “settled status” programme this summer, Rudd’s successor as home secretary, Sajid Javid, said the default position would be to grant rather than refuse applications.

But the government’s track record of errors in immigration enforcement and the lack of communication between the Home Office and applicants has raised concerns among lawyers who have read the guidance notes.

“If there is a presumption that people are going to get this then surely that should be spelled out in the guidance notes for the case workers,” said Luke Piper, a solicitor with South West Law, who is working with the campaign group the3million.

He added: “When it come to the context of the case worker processing applications, you have to think of their mindset and their approach. This guidance reads like any other Home Office guidance. It is not really giving clear scope to case workers. There has to be certainty and clarity on a seismic programme to register more than three million people if the Home Office is to deliver in such a short space of time.”

The case worker guidance has been issued as part of a live trial of the settled status registration scheme. It started last week with the Home Office seeking to recruit 4,000 EU citizens to test the process at three Liverpool universities and 12 NHS trusts in the north-west of England.

After Brexit all EU citizens will be required to sign up for settled status so as to continue working and receive benefits, including healthcare, in the UK. They have been promised an application process that is “streamlined and easy to use”.

The language in the case worker notes shows strong links to the existing immigration system for non-EU citizens, having more than 30 references to indefinite or limited leave to remain.

Colin Yeo, an immigration barrister and author of the Freedom of Movement blog, said: “The government is causing confusion by re-badging existing types of immigration status in order to make them sound more reassuring and comprehensible to EU citizens. But what is happening in reality is that EU citizens have to apply for and be granted the same form and type of immigration status as third-country nationals from outside the EU.”

The Home Office said the guidance notes were part of the trial and would be amended according to feedback.

A spokesman said: “EU citizens make a huge contribution to our economy and to our society and we want them to stay. We have been clear that we will support them through the settlement scheme application process to ensure they get the right answer, and this test phase is part of getting it right.”

The 59 pages take case workers through various points, from those able to apply (including non-EU family members), to eligible identity documents.

The government has made it clear that it expects the majority of applicants to sail through. The notes tell case workers: “You should work flexibly with applicants to help them evidence their continuous residence in the UK by the best means available to them.”

Barbara Drozdowicz, chief executive of the East European Resource Centre, said she welcomed the reference to working flexibly. “It remains to be seen if practice will follow the guidance. But the move is very welcome and hopefully would contribute to an overall change in practice in the treatment of lawfully residing non-British citizens of all origins,” she said.

Piper said there were concerns with some aspects of the guidance, such as how freelance workers or sole traders could provide evidence with their applications.

Anne-Laure Donskoy, one of the founders of the3million, expressed concern that there was not sufficient clarity about what types of criminal record would invalidate an application. She said some vulnerable people, such as homeless people or those with mental health issues, could be disqualified even if they had set out to be arrested just to get to a safe environment such as a police station.