Italy's president Sergio Mattarella has sent a message of condolence to Britain's head of state Queen Elizabeth II condemning the slaying of pro-European Labour MP Jo Cox by an alleged neo-Nazi suspect and loner.
"I express my personal solidarity and that of all Italians with the British people and the deepest sympathy for the family of Member of Parliament Helen Joanne Cox, the victim of a vile and hateful act," read the message.
"I am sure this latest act of unmentionable savagery can only strengthen the shared fight against every form of hatred and violence so that political debate can always remain free and open."
The far-right political party, Britain First, said it was “not involved” in Cox's brutal killing on Thursday near Leeds in northern England, and condemned it unequivocally.
But witnesses said the 52-year-old suspect arrested over the murder shouted "Britain first" several times as he attacked 41-year-old Cox, the mother of two small children, with a knife and a gun.
Britain First has been campaigning for an exit from the European Union in the 23 June referendum amid furious nationwide debate of issues such as immigration and the economy and personal recriminations.
Cox's murder prompted campaigning to be suspended in the EU referendum. Flags across Whitehall are flying at half-mast, while flags at Buckingham Palace and the Palace of Holyroodhouse in Edinburgh are also lowered in tribute.
Queen Elizabeth II has written privately to Cox's husband, Brendon, a Buckingham Palace spokesman said.
Police had been poised to step up security for Cox, who became an MP last year, as she had been reportedly harassed in a stream of abusive messages over the last three months.