London - Iceland will hold a national election on October 28 after the governing coalition collapsed amid a scandal about a proposed pardon for a sex offender.

President Gudni Th Johannesson said on Monday it was clear there was no chance of forming a new government from the existing parliament.

Prime Minister Bjarni Benediktsson resigned Saturday after one of the parties in his center-right coalition administration quit over an attempt by the prime minister's father to help clear the name of a convicted paedophile.

The centrist Bright Future party walked out after it emerged that Benediktsson's father had written a letter urging a pardon for Hjalti Sigurjon Hauksson, convicted in 2004 of raping his stepdaughter almost daily for 12 years.

The election comes a year after Iceland's last national vote, which was called after the former prime minister resigned amid protests over his offshore holdings that were revealed in the Panama Papers leak.