Hayward, who was elected to WA's parliament earlier this year, is facing multiple charges relating to an eight-year-old girl, including persistent sexual conduct.

The 52-year-old faced Perth Magistrates Court on Thursday and was not required to enter a plea. He was granted bail to reappear on December 13.

In a statement on Friday, the WA Nationals said they had received formal notice of Hayward's resignation from the party.

The party had already suspended his membership following an emergency meeting of the state executive.

Opposition Leader Mia Davies urged Hayward to quit parliament, saying her parliamentary colleagues agreed he should not retain his seat.

"Mr Hayward is facing serious charges, he has resigned his membership of our party and he should now resign from the parliament," the WA Nationals leader said on Friday.

"Our party took swift and immediate action in the hours after the matter was revealed, by suspending Mr Hayward, removing his membership rights and setting in motion procedures under The Nationals WA's constitution to consider his future.

"His resignation means we no longer need to pursue this action."

Ms Davies said she was shocked and distressed to learn of the allegations shortly before boarding a flight from Carnarvon earlier on Thursday.

She moved immediately to stand down Hayward from his shadow local government, water and regional cities portfolios.

"James has been in and around our party for some time. He's a colleague. You work very closely with people in this environment, so needless to say it's come as a shock to everybody that knows him," Ms Davies told reporters on Thursday.

Hayward, who was elected to represent the South West region in the Legislative Council at the March election, has been absent from parliament this week.

He previously worked as a local councillor in Bunbury and a television journalist and served as the WA Nationals' state president.

It is open to Hayward to remain a member of parliament while the matter is determined by the courts.

Police Minister Paul Papalia labelled the allegations disturbing but declined to comment further while it was before the courts.

Hayward was one of three MPs earlier this year who voted against a government bill to prevent people from picketing within 150m of facilities that provide abortion services.

The WA Nationals assumed opposition status after Labor's blowout victory in the March election left the Liberals with just two lower house seats.

Under their opposition alliance, the Nationals and Liberals hold a combined 16 seats in the 95-seat parliament.

The West Australian newspaper reported earlier this year that Hayward's television production company, Fiery Productions, had gone into liquidation over an alleged $440,000 tax debt.

Individuals convicted of persistent sexual conduct in WA face a maximum prison term of 20 years.

Australian Associated Press