Richard Lee spoke to Boris Johnson about his campaign for a public inquiry into the investigation into his daughter’s disappearance when the PM made a surprise visit to Hartlepool on Bank Holiday Monday.
It was after an earlier planned meeting in Downing Street was cancelled due to the crisis in Ukraine.
Following Monday’s meeting Richard said: "He is the only Prime Minister who said he would meet me and has followed through with his word.”
But after reflecting on the surprise meeting, Richard has now told how angry he felt at how it was arranged.
He was contacted by Hartlepool MP Jill Mortimer’s office last Thursday asking if he was free on Monday, then given a time to go “to clarify some points” about the case.
When he arrived he was told he would be meeting with Boris Johnson that day.
Richard, 72, said: “When Boris agreed to meet with me I said I would meet with him at Downing Street, because on the steps of Downing Street my case would have been spingboarded back into the headlines where she deserves to be.
"I understand about the need for security, but they couldn’t tell me that I was going to meet with the Prime Minister and keep it secret?
"I was seething that I had been drawn there under false pretences.
"When I came back home I realised I was, for want of a better word, ambushed.”
Katrice vanished on her second birthday on November 28, 1981, from a British military base in Paderborn, Germany, where Richard was serving as a sergeant in the Army.
He remains convinced she is still alive but has long campaigned over what he believes were mistakes made by the Royal Military Police and German Police in the initial investigation.
Richard feels the meeting would have been longer had it been in London, with police ushering the PM away after around 20 minutes.
A government spokesperson said: “The Prime Minister was pleased to meet with Mr. Lee this week to express his thoughts and sympathies with him and his family.
“They discussed Katrice Lee’s deeply tragic case and the Prime Minister offered his wholehearted support to Mr Lee.”