Tens of thousands of Italians have marched through Rome to protest against the formation of the new left-wing government under Prime Minister Massimo D'Alema.

The protest has been organised by a group of right-wing parties led by the media magnate and former prime minister, Silvio Berlusconi.

The lines of demonstrators have converged on a central square for an evening rally.

Mr Berlusconi told the crowd that freedom and democracy were under attack, and had to be defended.

The protestors are unhappy that Mr D'Alema's government has come to power without facing the electorate; it was appointed after presidential consultations following the collapse of the government of Romano Prodi.