MP Jeremy Corbyn
MP Jeremy CorbynReuters

One of the candidates to lead Britain's Labour party, Jeremy Corbyn, has come under scrutiny for comments he once made calling Islamist terrorist groups Hamas and Hezbollah his "friends."

As the Labour leadership race heats up, Corbyn has seen his controversial comments - and his decision to invite members of the terrorist groups to parliament in the first place - come back to haunt him, with the topic being brought up in successive interviews Monday.

But it seems the grilling was a little too much for Corbyn, who finally snapped during this interview with Channel 4:

He is one of four Labour MPs vying for leadership of the left-wing party, after former head Ed Miliband resigned following his failure to win May's general elections.

Corbyn is the most far-left of the candidates running, and despite attempting to strike a conciliatory in the interview is a patron of the extremist Palestine Solidarity Campaign. But his radical socialist policies have won him support from the powerful trade unions, whose backing helped Miliband secure a surprise victory during the last Labour leadership race.

However, a growing number of Labour supporters are calling on other members not to vote for him, warning the election of such an extreme candidate would render the party unelectable.

In the interview Corbyn also addressed the crises in Syria and Iraq, saying military intervention would not be effective and calling - perhaps unsurprisingly - for more engagement with Iran to help defeat ISIS.

Watch: Jeremy Corbyn calls Hamas, Hezbollah "my friends":