In a move that's likely to cause further consternation among his former colleagues, ex-Prime Minister Malcolm Turnbull – along with his wife Lucy and son Alex – appears to have got behind a grassroots campaign to oust his old political rival Tony Abbott from the seat of Warringah, which Mr Abbott has held since 1994.

A new Instagram account titled 'Vote Tony Out', which posted its first picture on Monday afternoon, counts the three Turnbulls among its early followers.

Malcolm Turnbull follows the account, along with wife Lucy and son Alex. Credit:Instagram

The account is operated by Manly resident Mark Kelly, who describes its content as "Warringah and it's [sic] citizens, why we don't like Tony Abbott, one story at a time."

Mr Kelly told the Herald he is working as "just one person in Manly" and has no political affiliations.