The Shadow Northern Secretary Mr Quentin Davies described the protest at a Catholic primary school in north Belfast as "utterly unacceptable".
Mr Davies accompanied parents and children as they returned from Holy Cross Girls' School, Ardoyne, yesterday afternoon.
The Conservative Party rejected the behaviour of residents who had been protesting against Catholic children using the street, he said. "Anybody who targets children puts themselves beyond the pale of civilised behaviour." His comments met with a hostile reception. Uncertain as to his identity, one demonstrator shouted: "Away back to the Free State Fenian scum." Mr Davies said: "These people I am afraid are completely frenzied with hatred for the other community. It is a very alarming and distressing situation."