Liz Truss has vowed to deport more migrants if she is elected prime minister.
The foreign secretary said she would strike more Rwanda-style deportation deals in a bid to halt small boats bringing illegal immigrants from France.
Truss, who is battling it out against Rishi Sunak for Boris Johnson’s job, also vowed to bolster Border Force staff by 20 per cent in a bid to deter people from crossing the Channel.
The pledges come as the leadership rivals struck a hard-line tone on immigration in a bid to win over Tory party members, who will pick their favourite for PM, with the result announced on September 5.
Sunak said he would give MPs control over who comes to the UK by creating an annual cap on the number of refugees accepted each year.
Both candidates have backed Priti Patel’s controversial policy of sending migrants to Rwanda, with Truss saying she would extend it to other countries.
Truss said: “We need to break the cycle of these appalling gangs and stop people taking dangerous journeys across the channel.
“As prime minister, I am determined to see the Rwanda policy through to full implementation as well as exploring other countries where we can work on similar partnerships.
“I’ll make sure we have the right levels of force and protection at our borders. I will not cower to the ECHR [European Convention on Human Rights] and its continued efforts to try and control immigration policy.”
Sunak said he will do “whatever it takes” to make the Rwanda scheme work, arguing that the UK’s current immigration system is “broken” and “chaotic”.
Also included in Truss’s policy pitch are plans to double Border Force Maritime staffing levels so that more Channel patrols can take place, as well as appointing a new Home Office minister to oversee the Border Force.
A source close to Truss said: “As foreign secretary, Liz worked closely with Priti Patel to formulate the generation-defining Rwanda policy.
“As prime minister she will do whatever it takes to protect our borders. She’s been frustrated with the ECHR and its mission creep. She is prepared to take a tougher stance and deliver the reforms required so the ECHR works for Britain.”
Sunak sought to match Truss on immigration with a 10-point plan that includes a commitment to a more narrow definition of who qualifies for asylum compared with that offered by the ECHR.
The plan will also give the government enhanced powers to detail, tag and monitor illegal migrants.
Sunak said: “Our immigration system is broken and we have to be honest about that. Whether you believe that migration should be high or low, we can all agree that it should be legal and controlled.
“Right now the system is chaotic, with law-abiding citizens seeing boats full of illegal immigrants coming from the safe country of France with our sailors and coastguards seemingly powerless to stop them.
“It must stop, and if I am prime minister I will stop it.”
Sunak said he would immediately work with French president Emmanuel Macron to find a solution to small boat crossings, including through a new cross-government taskforce.
Writing in the Sunday Telegraph, Sunak said: “The ECHR cannot inhibit our ability to properly control our borders and we shouldn’t let it. We need to inject a healthy dose of common sense into the system, and that is what my plan does.”
Labour’s shadow home secretary Yvette Cooper criticised the pair’s plans and said it risked wasting £120m of taxpayer money if it is ruled unlawful by courts.
The first deportation flight was grounded in June after a series of legal challenges were lodged, with more expected to be filed in due course.
Cooper said: “The Conservatives have been in power for 12 years. It beggars belief that they claim to be the ones to sort things out when they have both failed for so long.”
The shift on to immigration comes after Sunak and Truss repeatedly clashed over economic policy.
Truss has vowed to cut taxes “from day one” if she replaces Johnson and has said she would immediately scrap Sunak’s increase in national insurance, which she argued was strangling growth and hitting families already hard-pressed by the cost of living crisis.
Sunak retaliated by branding her tax-cutting plans as “immoral” and a “fairytale”. He said he will only cut tax when inflation — currently running at 9.4 per cent — was under control.
Over the next six weeks, Truss and Sunak will take part in a number of hustings across the country in a bid to woo Tory party members.
Polling from YouGov last week gave Truss a 24-point lead over Sunak among Tory party members.
However, new polling from Opinium put Sunak slightly ahead of his rival among all voters on the question of who would make the better prime minister.
Forty-three per cent of the 2,000 adults surveyed said Sunak would make a good prime minister, compared with 36 per cent for Truss.
The two will go head-to-head in a televised BBC debate on Monday, with The Sun and Talk TV staging another on Tuesday.
Sky News will then host another debate on August 4.