'Pro-life' US congressman resigns after allegedly asking his mistress to have an abortion

A “pro-life” US congressman will resign from politics after following allegations he asked a woman he was said to be having an affair with to get an abortion.

Following the allegations detailed in text messages with his mistress, Republican Representative Tim Murphy said in a statement on Wednesday he would not seek re-election next year.

The conservative politician had been a member of the Congressional Pro-Life Caucus, once receiving a 92 per cent score from the conservative Family Research Council, which opposes abortion.

Tim Murphy has resigned. Source: AAP

Citing a January 25 text message, The Pittsburgh Post-Gazette said the woman had chastised Murphy for asking her to get an abortion during a pregnancy scare despite his office posting an anti-abortion statement on Facebook.

• Vegan student has raw horse heart thrown at her as she slept in Melbourne university housing

• Taxi driver killed young Queensland woman who vanished 31 years ago, police say

• Pedestrian stabbed in Brisbane 'road rage' attack has died

According to the newspaper, Murphy texted her in response: "I get what you say about my March for life messages.

“I've never written them. Staff does them. I read them and winced. I told staff don't write any more. I will."

Murphy's extramarital affair had first been exposed in 2016 during the woman's divorce proceedings, the Post-Gazette reported.

Tim Murphy allegedly asked a woman with whom he was having an affair with to get an abortion. Source: AAP

The congressman will leave the Capitol on October 21 but his resignation will not affect the balance of power in the Republican-controlled House of Representatives.

Murphy, 65, who was first elected in 2002 to represent a southwestern Pennsylvania district, had been a commander in the US Navy Reserves and is a practicing psychologist, his office's website said.

On Wednesday, Murphy voted for passage of the Pain-Capable Unborn Child Protection Act, which would ban women from having abortions after 20 weeks of pregnancy in most cases, according to GovTrack, which follows congressional voting records.