Hillary Clinton launched an attack on the Tories during a speech at the University of Oxford.
She was highly critical of the MEPs from the Party who she claims have not challenged Viktor Orban, Hungary’s leader.
Recently the Conservative group at the European parliament voted against measures to censure Hungary over its policies to reduce judicial independence and boost control over the media.
Orban eventually lost the vote by 448-197.
She said: “I hope the EU and the people of Europe will resist the backsliding we are seeing in the east. It’s disheartening to watch Conservatives in Brussels vote to shield Viktor Orbán from censure, including British Tories.”
Mrs Clinton went on: “Let’s not be fooled by the masquerade that countries like Turkey and Hungary are still real democracies, just illiberal ones.
“Illiberal democracy is a contradiction in terms.”
Mrs Clinton added: “We can’t let fear or bias force us to give up the values that have made our democracies both great and good.
“Our goal should be to build societies that are secure and welcoming, where everyone counts and everyone contributes – people who are newcomers to our lands and people who have lived in the same place for generations.”
Ms Clinton speech was to help mark the 70th anniversary of the Universal Declaration of Human Rights (UDHR) at the Bonavero Institute of Human Rights at the University of Oxford.