The first small boat migrant has been sent back to France under the new 'one in, one out' returns deal, Home Office sources have confirmed.The Indian man was flown from London to Paris this morning, it is understood. A further migrant is due to be deported on another flight later today.As a result of the first deportation taking place, Britain will begin accepting other migrants from France as early as Saturday.The Home Office has been accepting online applications from migrants who are currently in France to come here, providing they have not 'previously been removed from the United Kingdom' and do not pose a 'national security or public order risk'.The number of migrants who will be admitted to Britain will equal the total who have been removed by that stage. Like those deported to France, they are likely to come here aboard a scheduled passenger flight. The first deportation comes after the Home Office suffered three days of aborted attempts under the deal signed in July by Prime Minister Sir Keir Starmer and French president Emmanuel Macron.Home Secretary Shabana Mahmood said: 'This is an important first step to securing our borders.'It sends a message to people crossing in small boats: if you enter the UK illegally, we will seek to remove you. An Air France Airbus jet pictured on the apron at London's Heathrow airport yesterday'I will continue to challenge any last-minute, vexatious attempts to frustrate a removal in the courts.'The UK will always play its part in helping those genuinely fleeing persecution, but this must be done through safe, legal, and managed routes – not dangerous crossings.'A high-profile legal challenge on Tuesday forced ministers to temporarily abandon attempts to remove a 25-year-old Eritrean man, who had been due to be aboard a 9am flight yesterday.The case led Ms Mahmood to condemn small boat migrants who lodge last-minute legal challenges.She said it ‘made a mockery of our laws’ when they tried to dodge deportation by claiming they were victims of ‘modern slavery’.But her Tory shadow Chris Philp said Labour had ‘been in denial’ about how the law works in immigration cases – and still lacks impetus for real change.He warned that Prime Minister Sir Keir Starmer and his Attorney General Lord Hermer – both former human rights barristers - will never allow meaningful reform of human rights and other laws used to overturn deportations. Home Secretary Shabana Mahmood has condemned small boat migrants who lodge 'vexatious' last-minute legal challengesMs Mahmood's criticism of last-minute legal challenges were the most robust acknowledgment yet made by a Labour minister of how they are deployed to frustrate deportation measures.But since the new returns deal with France was announced the Government has been repeatedly warned it was vulnerable to human rights and modern slavery claims.