Migrants who use illegal routes to access the UK will be routinely denied asylum in the country, under government plans.
Home Secretary Priti Patel is preparing to create a legal assumption that those who enter Britain illegally will not be granted asylum.
Ms Patel will on Sunday vow to explore "all practical measures" to deter illegal immigration – shrugging off controversy over Government proposals to process migrants offshore.
In an address to the Conservative Party's online conference, she is expected to describe the UK's asylum system as "fundamentally broken", saying ministers "have a responsibility to act".
She will pledge to crack down on foreign offenders using "meritless" asylum claims to remain in the country, while warning that that asylum seekers who come to the country legally and would face danger if they returned to their home countries, can be left languishing in the system.
She will also warn of the need to address migrants' ability to "shop around" for a state in which to claim asylum, often arriving in the UK illegally having first passed through numerous safe countries.
Ms Patel's intervention comes after a paper prepared for No 10 on the feasibility of using islands such as Ascension, St Helena and Papua New Guinea to process asylum seekers, was leaked last week.
The Home Secretary faced criticism that the idea was impractical, potentially illegal and expensive.
Although dismissed by the Government, senior officials maintained it was justified for civil servants and ministers to “brainstorm” and consider all options to combat the surge in migrants crossing the Channel.
In a speech outlining plans for an overhaul of the country's asylum system, Ms Patel is expected to say: “I will accelerate our operational response to illegal migration. We will continue to hunt down the criminal gangs who traffic people into our country.
"I will continue to use the full force of our outstanding National Crime Agency and intelligence agencies to go after them.
"We will make more immediate returns of those who come here illegally and break our rules, every single week.
"And we will explore all practical measures and options to deter illegal migration.”
The Telegraph has previously revealed that the Conservatives have been considering curbs to the country's human rights laws in order to help reduce spurious legal claims by migrants.
Ms Patel, whose parents fled to the UK from Uganda shortly before Idi Amin ordered the expulsion of the country's Asian minority community, will outline a vision for a "fair asylum system" which should "provide safe haven to those fleeing persecution, oppression or tyranny" – which she is expected to say that the UK fails to achieve.
She will add: “Right now, the most vulnerable are stuck in this broken system, with over 40,000 other people. Almost half of these claims take a year or more to reach a decision. Costing UK taxpayers over one billion pounds each year. The highest amount in almost two decades.”
Ms Patel will pledge to introduce a new system that is "firm and fair".
"We will stop the abuse of the broken system ... we will stop those who come here illegally making endless legal claims to remain... we will expedite the removal of those who have no claim for protection.
"After decades of inaction by successive governments we will address the moral, legal, practical problems with this broken system. Because what exists now is neither firm nor fair.
"And I will bring forward legislation to deliver on that commitment. I will take every necessary step to fix this broken system. Amounting to the biggest overhaul of our asylum system in decades.”