A new Home Office poster campaign that advises immigrants to "ask about going home" and offers to book them flights back to their native countries has been criticised by Scottish politicians as "shameful".

The adverts have been on display in immigration reporting centres in Glasgow and Hounslow in west London since the end of last month and will stay until 4 October.

The Home Office said the posters were designed to ensure people knew that immigration officials could provide them with "sensitive advice and assistance to help them return home with dignity" and to raise awareness of its "voluntary return scheme".

Earlier this month, ministers were threatened with court action over a Home Office publicity campaign in which vans touring six London boroughs carried the wording: "In the UK illegally? Go home or face arrest."

Opponents, among them the business secretary, Vince Cable, labelled the scheme an offensive stunt. Some critics said the "go home" wording was reminiscent of racist slogans from the 1970s.

Those attending the Glasgow and Hounslow immigration reporting centres include people applying for asylum, those appealing a decision to refuse them asylum and migrant workers with queries about their visas.

The adverts include signs on chairs that read: "Ask about going home" and posters with the wording: "Is life here hard? Going home is simple." One poster shows a photograph of an aircraft and reads: "This plane can take you home. We can book the tickets."

The campaign also includes an aeroplane-shaped poster suspended from the ceiling carrying the words: "Let us help you go home."

Sandra White, the SNP MSP for Glasgow Kelvin and a member of the Scottish parliament's cross-party group on asylum seekers, said: "Very many asylum seekers are fleeing for their lives, escaping violence and persecution. To be greeted with posters urging them to return to the countries they have just fled is totally inappropriate and appalling.

"In my view the campaign borders on the racist. The posters are in an area where most people who go there are African or Asian and to my mind they are there to put fear into people." White said the posters should be removed "as soon as possible". "They are clearly sending out a message saying: 'You are not welcome here and we want you to leave.'"

Ken MacIntosh, Labour MSP for Eastwood, said: "I think the whole 'go home' campaign has been damaging, and this latest campaign certainly seems to reflect the same sentiment.

"It is a shameful attempt to whip up anti-immigration feeling."

Rachel Robinson, policy officer at Liberty, the civil liberties campaign group, said: "Dismissive posters encouraging asylum seekers to go home reveal a depressing culture of disbelief in the Home Office.

"They also help explain the consistently poor-quality decision-making in asylum cases, overturned with sky-high frequency at appeal. The claims of those seeking protection from persecution should be treated with seriousness and respect, not gimmicky disregard."

All asylum seekers in Glasgow must report to the Home Office centre in Govan. How often they report depends on each individual, and can vary from once a week to once a month.

Most asylum seekers living in Scotland are from Africa and the Middle East, including hundreds who have fled conflicts in Iraq, Afghanistan and Syria.

An SNP MSP said he was writing to Theresa May, the home secretary, to demand that the campaign end immediately.

James Dornan, who represents Glasgow Cathcart, described the campaign as "xenophobic" and highlighted the humanitarian crisis in Syria.

He said: "I am writing to Theresa May to find out if she thinks this type of manipulative messaging to people in very difficult situations is appropriate or not. Did she authorise this campaign? And if not, does she approve of it? And will she commit to ending the use of this inflammatory language immediately?

"We only have to look at the terrible events in the Middle East right now to see what 'home' can be like for some of these people. There are upwards of 1,300 Syrian asylum seekers in the UK – undoubtedly including some in Glasgow – does the Westminster government really think it is appropriate to be telling people like them that it is 'easy' to 'go home'?

"There is no room for this type of abhorrent xenophobic campaign which will only serve to make already vulnerable people feel unwelcome and fans the flames of racial bigotry."

Dornan has also put down a motion in the Scottish parliament calling for the campaign to end and calling for Scotland to "have a humane asylum system".

He added: "The Home Office clearly has absolutely no idea about how modern Scotland treats vulnerable people – regardless of where they are from. Their campaign must stop immediately.

"I strongly condemn this poster campaign and urge them to reconsider this so-called pilot and remove their extreme tactics from Scotland."

A Home Office spokesman said asylum seekers attended the offices, but the majority of people attending the offices had no right to be in the UK.

He said: "Those with no right to remain in the UK should leave voluntarily. These posters are designed to ensure people know that we can provide sensitive advice and assistance to help them return home with dignity.

"We also continue to work closely with community groups who welcome the opportunity for someone who is not here legally to leave the country of their own accord."