After months of speculation, Miller today rose in parliament to formally resign – effective immediately – and rule out running for Ipswich mayor. The by-election will likely be held on March 28, to coincide with council elections and the Currumbin by-election prompted by the resignation of the Liberal National Party’s Jann Stuckey.

Miller spoke only briefly in parliament before handing a more expansive resignation letter to Speaker Curtis Pitt. Tearful, Miller stumbled on her return to the backbench, embraced by nearby LNP members and, later, some Labor members. She then left the Legislative Assembly for the last time.

In her letter, the 20-year veteran paid tribute to her constituents and particularly their anti-dumping push to avoid the city west of Brisbane becoming “Tipswich”. Again claiming to be the last of her generation of Labor MPs, Miller stopped short of directly criticising the Government.

“But the most important legacy I believe I leave is to Tell the Truth and Shame the Devil, be honest, to fight for our values and principles and never back down,” Miller wrote.

Miller, 61, had become more outspoken after she was forced to resign from Cabinet in 2015 due to integrity issues. She recently told ABC Radio that parliament had become a lonely place and she had faced internal pressure to give up her seat.

Opposition Leader Deb Frecklington took the opportunity to ask Premier Annastacia Palaszczuk whether she would act on Miller’s allegations she had been bullied and ostracised by the governing party.

However, with Stuckey having made similar claims against the LNP, Palaszczuk instead challenged all MPs to reflect on their conduct.

“Those in glass houses shouldn’t throw stones,” Palaszczuk said in question time.

Miller also revealed that, after a recent operation to remove a tumour, she had cause to reconsider her priorities. She finished with a message to her family: “I love you. It’s your turn now. I’m coming home.”

Palaszczuk thanked Miller and Stuckey for their service to their electorates and parliament.

Bundamba is considered a safe Labor seat, however there is still strong support for One Nation in the Ipswich region. Both by-elections will test the retiree’s personal following and whether their party has been tarnished by the circumstances of their departure.