A Fathers 4 Justice activist today handcuffed himself to the children's minister, Margaret Hodge, at a family law conference in Manchester.
The man attached himself to Ms Hodge at 10.11am and was arrested by police officers at 10.50am. The minister, freed from the man, went ahead with her speech as planned.
Fathers 4 Justice said Jolly Stanesby and Jason Hatch, who scaled Buckingham Palace dressed as Batman earlier this year, had made "a citizens arrest".
It is believed a third man tried to join them on the stage but was wrestled to the floor by lawyers sitting in the front row.
A Greater Manchester police spokesman said of the incident: "Police were called to the Lowry hotel after a man is believed to have entered a meeting being held in a function room and handcuffed himself to a government minister.
"Officers arrived at the hotel and the minister, who was attending the meeting, was freed from the handcuffs. She was unharmed and a man has been arrested in connection with the incident. The man involved is believed to have been representing Fathers 4 Justice."
The group, which campaigns for greater rights for fathers who have separated from their partners, has won notoriety for its publicity-grabbing stunts.
Mrs Hodge had another run-in with Fathers 4 Justice a week ago. Police had to hold back protesters when she arrived to deliver a speech near Bootle, in Merseyside, last Friday.
In an interview with Monday's Independent she said: "Divorce and separation is horrible for everybody, but the idea that the state can sort out entrenched animosity and bitterness in a relationship, I think, is stretching it a bit far."
In May, campaigners Ron Davis and Guy Harrison brought prime minister's questions to a halt when Harrison hurled a condom filled with glitter and flour at Tony Blair as Davis held a poster upside down and chanted slogans. Davis was given a two-year conditional discharge while Harrison was fined £600.
In February four protesters, including Hatch, dressed up as superheroes and scaled the Clifton suspension bridge in Bristol, causing traffic chaos. They were later found guilty of public order offences.
And in January Mr Stanesby climbed the gantry of the Tamar bridge, near Plymouth. He was joined by Jayne Woodman, a human resources manager from Swansea, who was the first woman to protest on behalf of the group. The demonstration caused long tailbacks on both the Devon and Cornwall approaches to the bridge when the pair blocked the carriageway with two cars.