Nigel Farage said he wants to bring immigration into Britain "back to normality," with numbers similar to those seen before 2000.
"Net migration into Britain varied between about 20,000 and 50,000 a year," the Ukip leader told Good Morning Britain.
"The effect of Ukip policies will be to bring us back to those sort of numbers," he said.
"What we're pushing here represents a drastic cut."
A protest has taken place at Yarl's Wood detention centre tonight after a Channel 4 investigation uncovered allegations that inmates were described by staff as "animals".
A spokesman for Bedfordshire Police said it was aware of a "small" and "peaceful" protest at the immigration removal centre.
A Serco spokesman said around a dozen women were involved in the demonstration and "we are talking to them".
A three-time Yarl's Wood detainee tells ITV News about her experience at the detention centre in Bedfordshire.Read the full story ›
Shadow home secretary Yvette Cooper has claimed today that calls for an independent inquiry into the problems at Yarl's Wood detention centre were dismissed by Theresa May.
Cooper said there had been a history of problems at the holding centre but the Home Secretary had refused calls to investigate.
She said: "There is no point in ministers pretending to be shocked at news of abuse. This is not news. Even now, the ministers have not set up an independent inquiry, Serco has."
Two staff members at the Yarl's Wood detention centre have been suspended from duty following the broadcast of a Channel 4 News investigation which revealed questions over standards of care at the holding facility.
Home Office Minister Karen Bradley told MPs today that the Serco employees were suspended over "serious and deeply concerning" allegations which were made after staff were filmed referring to the detention centre's inmates as "animals" and "beasties".
Ms Bradley said: "Serco immediately suspended one member of staff who could be identified from information available before broadcast and have suspended another having seen the footage."
The UK's current immigration detention practices are "expensive, ineffective and unjust", according to the head of a government panel investigating the treatment of foreign detainees.
MP Sarah Teather made her comments on behalf of the All Party Parliamentary Group on refugees and migration (APPG) after the group produced a report which suggests Home Office standard practices fall well short of the government's policy to use detention as a last resort.
The group made suggestions on how to improve Britain's immigration detention system including:
- Capping the immigration detention period to 28 days
- Getting the UK government to look at alternatives to detention including allowing individuals to live in the community
- Making it a policy not to detain women who are victims of rape and sexual violence, or who are pregnant, for immigration purposes
- Improving screening processes to ensure that victims of trafficking are not detained
Calls have been made for an immigration detention cap to be introduced that will restrict the holding of detainees to a maximum of 28 days.
The recommendations for a detention cap are highlighted in a report, produced by a cross-party group of MPs and peers, which suggests Home Office officials are "failing to follow guidance" on using immigration detention sparingly and for the shortest period possible.
Conservative MP David Burrowes, a member of the All Party Parliamentary Group on refugees and on migration (APPG) who produced the report, said an "urgent rethink" of the current detention system was needed.
He said: "The lack of a time limit is resulting in people being locked up for months and, in some cases, several years purely for administrative reasons.
"While there is a need to properly control our borders, people who arrive by fair means or foul must also be treated with dignity and respect throughout the immigration process."
Currently the UK is the only EU country not to have an upper time limit on detention, a factor which the APPG suggest has "significant mental health costs" for detainees.
The Government has officially failed to deliver on its pledge to cut net migration before the next election after official figures revealed an increase in the number of people coming to the UK.
Net long-term migration to the UK increased to 298,000 in the year ending September 2014 - an increase from 210,000 in the previous year, the Office for National Statistics said.
The rise was driven by "statistically significant increases" in the number of EU and non-EU migrants entering the UK, the ONS said.
A total of 624,000 people immigrated to the UK in the year to September - up from 530,000 in the previous 12 months.
The figures will be a blow to David Cameron who, along with Home Secretary Theresa May, had vowed to slash net migration to below 100,000 by the end of the current parliamentary term.
New study says migrant voters could have a "decisive" impact in a range of key marginal seats in the forthcoming general election.Read the full story ›
Health is still seen as the top priority for political parties in the forthcoming general election, according to the results of a ComRes roll for ITV News.
Half of all respondents said health is the most important issue, closely followed by controlling immigration (49%).
Labour (32%) is the party most trusted on the NHS, while Ukip (33%) is the party most trusted to control immigration.
Two in five people (21%) said they trust the Conservative Party most to control immigration - a five percentage point increase since the last poll.