The girlfriend of the former Ukip leader Henry Bolton has defended some of her offensive comments that led to him being deposed, saying she was trying to highlight a valid issue by describing Grenfell Tower as “nest of illegal immigrants”.

In an interview alongside Bolton on ITV’s This Morning, Jo Marney said her choice of language was “not good at all”, but she believed it was worth raising the immigration status of the people living in the west London tower, where 71 people died in a fire in June.

Bolton also sought to provide what he called context for other offensive messages sent by Marney, saying there was a wider problem of young people using social media. “There are far worse comments made by other people,” he said on Thursday.

Ukip has also announced that Bolton has now formally resigned as leader and left the party. He was ejected by a vote on Saturday at an emergency general meeting of party members called following reports about Marney’s comments.

Bolton, 54, and Marney, a 25-year-old model and Ukip activist, began their relationship at Christmas. They said it had ended while he tried to keep his job, but they are officially a couple again.

Asked about her comments on social media about Grenfell, Marney accepted that the language had caused offence, but said: “I meant what I said that there is an issue with illegal immigration in this country, and I think it’s something we should be discussing.”

Bolton said: “Jo has used emotive language, but actually they shouldn’t allow that to take away from the problem.”

Marney was more contrite about racist language she had used about Meghan Markle, Prince Harry’s fiancee, saying it was “disgusting” and “meant to shock”.

Bolton said: “It doesn’t make it OK, but what we have is a social context there that many of us, who are slightly older, find abhorrent, but it is quite common, quite normal, in social interaction in that domain” of social media.

Bolton is still married to his wife, Tatiana Smurova-Bolton, with whom he has two daughters aged four and 21 months. She lives in Vienna, where she works for the Organization for Security and Cooperation in Europe to support the family.

During the interview, the co-host Phillip Schofield read Bolton a message from his wife in which she said the past two months had been “horrendous for me and my family”, and that Bolton had not seen his daughters during that time.

“Rather than trying to protect the privacy of people who he hurt so badly, my still-husband has given countless interviews proclaiming his feelings for his lover, while still being legally married, and up until very recently saying, at the same time, to me that he wants our family to have a second chance,” she said.

Bolton said: “I’ve brought about a situation which has caused a lot of people hurt and distress. I am very, very sorry for that, of course I am.”