Rishi Sunak’s deportation flights to Rwanda, the cornerstone of the government’s immigration policy, could begin as early as 24 June, court papers seen by the Guardian show. Government sources had indicated that the first flights carrying asylum seekers would take off in July, but a court order released on Friday has disclosed that the government now says flights could take off in late June. The change has been revealed in a court order from Mr Justice Chamberlain, who is presiding over a legal challenge by the FDA union against the government. Correspondence released on Friday shows that government lawyers told the court in May that “the earliest a removal is expected to take place is 1 to 15 July 2024”. But government lawyers have now issued a clarification that says: “In the prime minister’s press conference on 22 April he said the first flight would leave in 10 to 12 weeks. The 10th week after 22 April starts with the week commencing 24 June. “We are instructed that this is the earliest possible date for the first removals and that the decision on the precise date will be based on operational considerations and progress over the coming weeks.” The date of the flights has been a closely guarded secret in Whitehall. Dozens of asylum seekers have been detained over the last 12 days. Ministers wish to avoid legal challenges based on the timing of the flights as well as campaigners attempting to block transport to and from airfields. The FDA union is challenging the government’s Rwanda policy on the basis that it is unlawful because it requires civil servants to ignore injunctions from the European court of human rights and thereby break international law, in breach of the civil service code. Keir Starmer said on Friday that he would scrap Rwanda flights immediately after entering Downing Street but that a Labour government would not bring back people already deported to the African country. He said Sunak was likely to get flights off the ground before the general election, and he insisted the policy would not work in deterring Channel crossings. Starmer pledged to divert funding from the Rwanda scheme – which has been estimated to cost £541m over five years – to create a new border security command of specialist enforcement officers and investigators. More than 9,000 people have arrived in the UK after crossing the Channel in small boats so far this year. In a message to smuggling gangs, Starmer said: “These shores will become hostile territory for you. We will find you. We will stop you. We will protect your victims with the border security command. We will secure Britain’s borders.” Provisional Home Office figures show 211 people made the journey from France to the UK on Thursday in three boats. This suggests an average of about 70 people per boat, and takes the provisional total for Channel crossings in 2024 to date to 9,037. This is up 35% on this time last year, when 6,691 crossings had been recorded, and a 16% rise compared with the same period in 2022 (7,801).