Theresa May has claimed the Labour leader Jeremy Corbyn is unfit to be Prime Minister because he "never backs Britain".
In a heated exchange during Prime Minister's Questions, Mrs May said the opposition leader should "never be" in charge of the country because of the "relationships he supports".
"When people were killed in Salisbury, his sympathies were with Russia," she said. "When terrorists were killing our people, his sympathies were with the IRA. In the recent tanker attacks in the Gulf, his sympathies were with Iran."
"He never backs Britain and he should never be Prime Minister."
Her comments came after Corbyn pressed Mrs May to cease arms sales to Saudi Arabia, following the murder of journalist Jamal Khashoggi in October last year.
The Washington Post columnist died at the Saudi Consulate in Istanbul, and US officials have claimed that Saudi Crown Prince, Mohammed bin Salman, ordered the killing.
However, Mrs May said she had raised the death with King Salman and the Crown Prince at the G20 Summit last year.
"He [Corbyn] is talking about the relations we have with Saudi Arabia. That is a relationship that has saved the lives of British citizens in the past," Mrs May added.
"We expect Saudi Arabia to take the right measures".
She continued: "The Rt Hon gentleman says to me bring about peace in the Yemen - that's exactly what we are working with out international partners to do through the United Nations and through the Yemen Quad."