Fathers 4 Justice campaigners attempted to storm the offices of the NSPCC on Monday, claiming the children's charity is biased against fathers.
Around half a dozen protesters tried to enter the offices, but were stopped by police, who had been tipped off.
A statement from Fathers 4 Justice said: "We criticise the NSPCC's portrayal of men as violent abusers when the majority of abuse perpetrated on children is by their mothers, according to the NSPCC's own research."
But the NSPCC says the group's claims are greatly exaggerated. A spokesman said: "Our research shows that mothers are responsible for 49 per cent of violent incidents against children in the home, and fathers for 40 per cent. Nine out of 10 sexual abusers are men and children are more likely to be scared of their fathers."