Julia Gillard’s ex-partner faces a criminal conviction after admitting he sexually assaulted a woman weeks before the former prime minister publicly announced their split.

Tim Mathieson, 66, will face a plea hearing in Melbourne Magistrates Court in October.

Mathieson, who faced court by videolink under the name Raymond Mathieson on Thursday, admits sucking on a woman’s nipple without her consent in East Brunswick in March last year.

Two weeks later Ms Gillard told the Adelaide Advertiser the couple had split more than a year earlier.

She and Mathieson, a former hairdresser, were together for a decade and lived at the The Lodge and Kirribilli House throughout Ms Gillard’s three-year term as prime minister.

Mathieson’s lawyer Brad Penno had asked in a previous hearing for his client to be granted diversion out of the justice system, which would allow him to avoid a criminal conviction.

On Thursday Mr Penno said that had been taken off the table and asked for an adjournment for a pre-sentence hearing.

Mathieson will return to court on October 19.

1800 RESPECT (1800 737 732)

National Sexual Abuse and Redress Support Service 1800 211 028

– AAP