Iain Duncan Smith has launched an attack on the Conservative MPs who forced him to resign as party leader.

In an interview with the Roman Catholic newspaper, Briefing, the Chingford MP argued that getting the party to adopt his social justice policy was "like shining a pencil torch into a dark void".

"In terms of the parliamentary party, the challenge was there," he said.

"I was able to establish the nature of the challenge, but I was not able to get my parliamentary party to embark on that journey.

"We are going to carry this on. I will win this one way or the other. All politics now needs a dose of reality and the Conservative Party needs desperately to understand the missing bit of the equation which is that social justice should be a Conservative cry.

"I want my colleagues to see the bit they perhaps didn't get - reclaiming the social justice agenda."

Without doing so, the party would find it "very difficult" to connect with voters, he argued.

"I don't regret what I did, how I did it or why I did it one little bit," he added.

"I have challenged my party and that was right. I hope others will now go on to pick up that challenge.

"I hope they don't just reach for the comfort blanket and say all we have to do is go back to the things that are tried and tested for the metropolitan media when that is part of the problem."

Duncan Smith's comments came as friends and associates expressed concern over his post-leadership life.

"People do not realise that this is a strangely emotional guy," one ally told the Times on Wednesday.

"I know that he comes across as wooden, but he is not like that at all. He feels the hurt and disappointment keenly. He gave everything he had to the job, but he was brought down by well-organised plotters"

Duncan Smith is still facing a parliamentary investigation into allegations that he wrongly hired his wife Betsy as a secretary.

The publication of the report by standards commissioner Sir Philip Mawer has been delayed.

"He is hoping to be more productive," the ally added.

"But he cannot do anything until (Sir Philip's) investigation is concluded. He is angry that the investigation is still hanging over him after the commissioner promised it would be swift."

In his interview the former leader also warned against attacks on his family.

"If you want to attack me, attack me, but don't for God's sake use my wife," he said.

"That was the bit I had the greatest level of anger about, even though she coped fantastically.

"She is tougher than all these people. She is stronger than the whole of the parliamentary party plus all of these journalists put together. She would make them look pretty weak."