hen news of government plans to send migrants to Ascension Island broke in the Financial Times on Tuesday night, sources close to the home secretary, Priti Patel, were quick to distance her from the idea of building asylum seeker detention facilities on remote volcanic outcrops in the Atlantic Ocean. “The home secretary would not want something like this,” one ally insisted. Government documents seen by the Guardian appear to lend credence to the idea that the home secretary is not behind the plan. It was Downing Street. Exactly who in No 10 is the driving force behind the idea of creating offshore detention facilities is not known. One Whitehall source said only it was “officials in the office of the prime minister”. At the request of Downing Street, the documents seen by the Guardian summarise advice from the Foreign, Commonwealth and Development Office (FCDO) about “potential offshoring of asylum processing centres for those using clandestine entry routes to the UK”. The documents make clear that the idea that three specific countries – Moldova, Morocco and Papua New Guinea – might make suitable destinations for asylum processing centres came from Downing Street. One document suggests Boris Johnson is personally across the plan, stating: “In addition to the work on OT [British overseas territory] options, the PM has asked for FCDO advice on potential third-country locations. We are asked to suggest options for a UK scheme similar to the Australian agreement with Papua New Guinea.” People in Conservative policy circles have for years talked of imitating aspects of the Australian immigration system, including the well-rehearsed “Australian-style points system” that involves replacing the UK’s existing immigration rules with a system ranking immigrants in order of preference based on their education or skills. Offshore asylum processing centres, however, would be far more controversial. They originated in Australia in 2013 as part of an effort to reduce arrivals by boat. Those who reached Australia would be resettled in detention facilities on Papua New Guinea or the nearby island nation of Nauru. The effectiveness of the policy is questionable. The Australian government claims that the policy has reduced the number of illegal maritime arrivals to zero. According to the Foreign Office advice seen by the Guardian, however, Canberra has tweaked the definition of “maritime arrival” so as to be able to make it. The detention facilities are also the subject of serious criticism by international observers and human rights groups. Appalling accounts of abuse and suffering have previously emerged from the camps, despite attempts to restrict independent reporting. Four years ago a huge cache of documents leaked to Guardian Australia documented 2,000 incidents including cases of violence, child abuse and self-harm suffered by those confined to the Nauru facility. More than half of the incident reports involved children. Children as young as eight or 10 detained at the facility had been witnessed experiencing suicidal thoughts, according to a professor of psychiatry working with families at the Nauru facility in 2018. The idea of replicating Australia’s notoriously hardline asylum centres has not been seriously discussed in the UK, though an increase in attempted Channel crossings over the summer, which has been covered extensively in the media, may partly explain the appetite for such a radical plan. Asked about the Ascension Island proposal on Wednesday, the Conservative MP Laura Trott said she was unaware of the details, but added: “We have increasing numbers of boats coming across the Channel. It’s an incredibly dangerous crossing. We need to stop people doing it.” According to one of the documents, the immigration minister, Chris Philp, spoke with Australian Border Force commissioner, Michael Outram, to “learn more about Australia’s approach” in June, while UK border force officials met their Australian counterparts in August. While there may be elements within the Home Office who favour the idea of offshoring asylum processing centres, the documents suggest Foreign Office officials are opposed to the ideas so far floated by Downing Street. FCDO officials found fault with all three possible countries as potential partners in such an endeavour. Morocco, they said, had already rejected a similar proposal from the European Union suggested in 2018, along with five other north African countries. It would be unlikely to entertain a similar suggestion from the UK because of its preference for a “balanced approach to migration in multilateral fora”, as well as ambitions for a leadership role in north Africa more broadly, they added. Papua New Guinea had been “scarred by the experience of holding asylum seekers on Manus Island”, the officials advised. Furthermore such a partnership would entail significant practical challenges, not least of which would be the two countries being 8,500 miles apart and with no direct flights. Moldova would not be appropriate due to a protracted conflict within its borders, including the illegal presence of foreign troops, as well as “endemic” corruption within the state apparatus. An annexe incorporates what appears to be advice from the Home Office on changes that would need to be made to UK legislation to bring an offshore asylum processing policy into effect. “Primary legislation is required currently as we are bound by European directives that prohibit offshoring, so the earliest a legislative change could take place would be January 2021,” it states. That would involve changing the law so that asylum seekers could be removed from the UK while their applications were processed, the creation of government powers to enable those seeking asylum to be sent overseas and a host of other provisions, including ensuring applicants could appeal within the UK legal system. The advice speculates that the proposals to put detention facilities on St Helena could be so unpopular with residents and elected representatives on the island that the UK government might need to impose it, warning of “major implications” for the relationship with overseas territories more broadly. Asked for comment, Downing Street referred the Guardian to comments earlier in the day from the prime minister’s spokesman when he was asked about the FT story. “Tens of thousands of people have rebuilt their lives in the UK and we will continue to provide safe and legal routes in the future,” he said. “As ministers have said we are developing plans to reform policies and laws around illegal migration and asylum, to ensure we are able to provide protection to those who need it while preventing abuse of the system and the criminality associated with it, and the rise in gang-facilitated Channel crossings has put this issue into sharp focus. “As part of that work we have been looking at what a whole host of other countries do to inform a plan for the UK.” The Foreign Office referred the Guardian to the Home Office. The Home Office said it had nothing to add to the comments from the prime minister’s spokesman.