Nigel Farage, the former leader of the UK’s Brexit party, has drawn criticism on social media from Wimbledon champion Andy Murray and others after attacking Australia’s treatment of Novak Djokovic and visiting the player’s family in Belgrade. Farage, who has long praised Australia’s strict immigration policies and demanded the British government “take back control” of the country’s borders, on Monday tweeted his satisfaction after a judge ruled a government decision last week to revoke the tennis star’s visa was “unreasonable”. The decision was “a huge win for @DjokerNole this morning”, Farage said, when Djokovic was released from immigration detention after winning his challenge to remain in the country and pursue his attempt at a record 21st grand slam title. Farage also told GB News that if – as he is entitled to do – the country’s immigration minister, Alex Hawke, decided to intervene and withdraw Djokovic’s visa once more on different grounds, Australia would resemble a banana republic. “I mean, is Australia a country based on the rule of law, or is it a country where governments can exercise arbitrary power?” Farage said. “If that judgment this morning is overruled, what’s the difference between Australia and a banana republic?” He said Australian authorities had used “really nasty tactics” against Djokovic, and called judge Anthony Kelly’s decision “the first really big victory” against “the big state, which has grown so much over the past two years of the pandemic”. Britain’s former world tennis No 1, Andy Murray, was one of many critics, retweeting a video of Farage with Djokovic’s family in the player’s trophy room and telling him to: “Please record the awkward moment when you tell them you’ve spent most of your career campaigning to have people from eastern Europe deported.” Farage replied: “Dear Andy, you clearly don’t understand politics or the Brexit campaign but are filled with prejudice. Concentrate on the tennis and, a word of advice, crack a smile every now and again.” Murray responded with an emoji of a fish hooked on a line, seemingly implying he thought the former politician had swallowed the bait. Djokovic, a long-time vocal opponent of mandatory vaccination, told border officials he was unvaccinated and had had Covid-19 twice, with the more recent positive test dated 16 December, according to a transcript of his interview with customs officials. Kelly said it appeared Djokovic had received medical exemption from Covid-19 vaccination on the basis of that infection, and ruled the player was not given enough time to consult advisers so he could respond fully to the cancellation decision. Farage said he “believed firmly in freedom of choice” and if Djokovic had decided not to be vaccinated, that should be up to him. Australia’s immigration rules allow Hawke to use separate, personal powers to cancel the player’s visa as long as the minister is satisfied “a ground exists” to do so; that Djokovic can’t dissuade him of this; and that it would be “in the public interest”. Mary Crock, an immigration law professor, has said the country’s Migration Act gives immigration ministers “god-like powers” to cancel visas. “Everything that has gone before can be disregarded,” she said. “It is set up precisely for this situation.” Both before and since the Brexit referendum, however, Farage has consistently sung the praises of Australia’s tough immigration system, arguing that being able to emulate it was one of the main advantages for the UK of leaving the EU. “An Australian-style points system can be used to increase or decrease immigration numbers,” he tweeted in June 2019. “Does Boris Johnson want to reduce the numbers? I don’t think so.” In October 2015, he said: “If you want to take back control of your borders so that we can have an Australian-style immigration system, you have to vote to LeaveEU.” The following year, he tweeted that it was “clear now that for our national security as as for social cohesion we must leave EU and have Australian-style immigration system”. Andrew Bridgen, a prominent Conservative Eurosceptic and long-term supporter of tougher UK immigration laws, tweeted his support for Farage’s view, saying the Australian government had “got itself into a real mess” over the Djokovic affair and “overruling the judge and deporting him now would … make it worse”. The actor, activist and vocal Covid lockdown sceptic Laurence Fox also tweeted his backing for Djokovic, describing the player as “an inspiration” and adding: “You have shown that if one person stands, however powerful, that many can stand alongside them. Thank you. Now please go and win!” Asked if Djokovic should be allowed to compete at Wimbledon if he has not been vaccinated, the British prime minister, Boris Johnson, said it was “important for the Australian authorities to make their own dispositions” adding: “I believe in vaccination.”