The government's controversial 'racist van' scheme has been grounded after the Advertising Standards Authority (ASA) found it to be inaccurate.
The watchdog cleared the campaign of being offensive and irresponsible, but criticised the Home Office for using arrest statistics which did not relate to the specific areas in which the vans appeared.
"The ad must not appear again in its current form," the ASA report said.
"We told the Home Office to ensure that in future they held adequate substantiation for their advertising claims and that qualifications were presented clearly."
But the ASA ruling is likely to disappoint campaigners who believed the adverts purposefully echoed rhetoric from the National Front in the 1970's.
The vans drove around mixed areas of London, including Barking and Dagenham, Redbridge, Barnet, Brent, Ealing and Hounslow, for two weeks with the message: "In the UK illegally?... GO HOME OR FACE ARREST."
While the ASA accepted that the slogan 'go home' had in the past been used to attack immigrants, it found that the adverts were now using it in a different context.
It said the phrase was "clearly addressed to illegal immigrants rather than to non-naturalised immigrants who were in the UK legally or to UK citizens, and it would be understood by those who saw it as communicating a message in relation to their immigration status, not their race or ethnicity".
It added: "We concluded that the poster was unlikely to incite or exacerbate racial hatred and tensions in multicultural communities.
"It was not irresponsible and did not contain anything which was likely to condone or encourage violence or anti-social behaviour."
There has been no news on whether the pilot will be expanded, although the fierce controversy which raged after the initial project is likely to have discouraged ministers.
"We are pleased the ASA has concluded that our pilot was neither offensive nor irresponsible," a Home Office spokesperson said.
"We have always been clear that this campaign was about encouraging illegal immigrants to leave the country voluntarily and was not targeted at particular racial or ethnic groups.
"In respect of the ASA's other findings, we can confirm that the poster will not be used again in its current format."