Campaign group Fathers 4 Justice is to disband, following reports linking it to a plan to kidnap Tony Blair's son, founder member Matt O'Connor has said.
Fathers 4 Justice staged a number of high profile demonstrations
Fringe elements of the group were said to have talked about holding Leo Blair, five, to highlight the cause of fathers denied access to their children.
Mr O'Connor told Channel 4 News the group could not continue after negative publicity generated by the allegations.
The group became known with a number of protests at public landmarks.
A Downing Street spokesman has said there will be no comment on the announcement.
Mr O'Connor said: "Three years after starting the organisation, we are going to cease all operations and bring the campaign to a close purely on the basis of what's happened."
He added that in recent months "extremist elements" had "undermined the position and credibility of an organisation that was flying along for the first two years of its existence".
Two members hurl packets of flour at Tony Blair in the House of Commons
One protester scales Buckingham Palace walls dressed as Batman
Five demonstrators climb to a Foreign Office balcony dressed as superheroes
Earlier the group had said it was suspending its activities pending an inquiry into the claims in the Sun newspaper regarding the prime minister's youngest son.
Mr O'Connor said he was now "past caring" what happened to Fathers 4 Justice.
"I want to get a good night's sleep. This is not what I wanted. I don't want to be associated with an organisation getting headlines like this," he said.
The group expelled 30 people last year in a bid to get rid of so-called extreme elements.
The organisation, which was committed to improving the rights of fathers who are estranged from their children, had staged a number of headline-grabbing stunts in recent years.
Protests included members throwing dyed flour at the prime minister in the Commons chamber and a protester dressed as Batman perching on a Buckingham Palace ledge for around four hours.
Police sources told the BBC that they were aware of a plan to abduct Leo, but said the plot only got as far as the "chattering stage".
There has been no kidnap attempt and no arrests regarding the matter.