Zia Yusuf told a small boat migrant who had been refused asylum in a host of European countries that he would be deported if Nigel Farage wins the next election.
Ashraf, who crossed the Channel, told BBC Question Time he tried to seek sanctuary in Turkey, Macedonia, Serbia, Romania, Austria and Germany.
But he reached the UK five years ago and has been allowed to stay.
And Question Time host Fiona Bruce asked Mr Yusuf if migrants such as Ashraf would be deported under a Reform Government.
He replied: “I don’t know enough about that particular story.
“In terms of broad strokes, if you are entering from a war zone, it is generally women and children first and the vast majority of the people coming to this country, via the English Channel, illegally, are men.
“That is a statistical fact. When people talk about language, I don’t know what language people are objecting to.
“I’m dealing with statistics, I’m dealing with data and I think that is a sensible way to formulate policy.
“And I think we should use language clearly and I think we should use language accurately.”
Ms Bruce pointed out Mr Farage has vowed to deport all illegal migrants living in the UK, like Ashraf.
Mr Yusuf said: “Absolutely.
“If you are in this country illegally, let me be crystal clear. If Nigel Farage is our next Prime Minister and that obviously what we’re working to deliver, if you’re in this country illegally, you will be deported back to the country from which you came.
“I have used the word invasion before and people might object to that term, but the dictionary definition of an invasion is an unwanted incursion into a space of land.
“And I don’t know what to describe it, 170,000 people arriving, by the way, what are the countries from which they are coming?
“They are coming from Syria. They are coming from Afghanistan, they’re coming from Iraq.”
And a furious row broke out after a second small boat migrant, from Iran, discussed whether he would be willing to go back.
He told the programme: “I have a four-month-old born here. She’s growing up here, learning English, learning how to read and write English. She won’t know how to read and write Farsi, or even speak Farsi.
“After five years, the Government of Reform, with someone who came from a migrant family telling me to go back to my country, what will happen to my daughter?”
Mr Yusuf hit back: “My parents came here legally. They did not come here illegally. There’s a clear dividing line in British politics.
“If you want to vote for a party that will prioritise the interests of foreign nationals who came here illegally, or do you want to vote for a party that is going to prioritise British citizens who work hard, set their alarm clocks before going to bed and toil to pay taxes.”
The Liberal Democrat’s Daisy Cooper interjected, saying “that is not the dividing line.”
The pair then shouted over each other as they clashed over benefits for migrants, with Mr Yusuf highlighting the £10bn Universal Credit bill for foreign nationals last year.
Green Party leader Zack Polanski then claimed Reform wants to take £49 a week off of asylum seekers.
Ms Cooper then tried to blame Brexit for the lack of returns.
Tory Shadow Justice Secretary Kieran Mullan hit back: “That is utter nonsense.
“If it is because of Brexit, why are people arriving in boats in Italy and Spain? We took more people under the returns agreement than we sent back.”