A QUEENSLAND MP exposed as a serial sexter apologised for the shame and embarrassment he caused his wife and children when he stepped down as chair of the ethics committee.

Redlands LNP MP Peter Dowling sent images to his secret mistress, including a picture of his penis plonked in a glass of red wine.

He is also accused of taking advantage of parliamentary travel trips to meet his mistress in locations including Perth and New Zealand.

The allegations are made in a letter from Mr Dowling's former lover to Speaker Fiona Simpson.

The Courier-Mail says it has seen several explicit text messages sent from Mr Dowling's mobile phone to the woman, including a picture of his penis in a glass of red wine, a self-shot image of his crotch while wearing boxer shorts and a full frontal picture of his genitalia.

Mr Dowling was first to speak as Queensland Parliament sittings opened for the week, apologising to his family and colleagues.

He claimed he had not breached parliament travel guidelines, including more than $20,000 in free upgraded flights.

"I'm not proud of the events plastered all over today's paper," he said.

"I can't and won't defend any part of it.

"I owe my staff an apology for the calls and emails they will no doubt be fielding.

"I owe my colleagues and fellow members an apology for any embarrassment or any poor reflection on the party.

"I do not wish for this issue and for my family to be dragged through the media any longer than necessary."

Mr Dowling has asked the clerk of parliament to consider the matters as he stepped down as Ethics Committee chair.

He asked for his family's privacy and for a "swift resolution".

"I will answer any question, front any investigation and inquiry as it relates to my work as Member for Redlands," he said.

Premier Campbell Newman asked all MPs to respect the process when he addressed parliament on Tuesday.

After a question from the Opposition during question time about why the matter had not been referred to the Crime and Misconduct Commission, Mr Newman said he had fulfilled his obligations.

He said he learned of the obligations about 5.30pm on Monday and was advised the matter should be referred to the clerk.

Opposition leader Annastacia Palaszczuk said Mr Dowling had done the "right and honourable" thing in standing down.

Back in May, Mr Dowling came under fire after he tweeted: "LABOR had sex with Queensland for the last decade."

Mr Dowling had jumped to the LNP's defence on Twitter after Treasurer Tim Nicholls tweeted a photograph of himself and the Queensland Premier Campbell Newman drinking whisky on the Gold Coast on Thursday night.

Leanne Donaldson, Labor's candidate for the seat of Hinkler, quipped: "Are you celebrating screwing over Queenslanders?"

Mr Dowling replied: "No. We are getting Qld back on track! Labor had sex with Qld for last decade or more. Your bad."

His comments were described as "childish at best" by Australian Christian Lobby state director Wendy Francis.