Federal politicians are under pressure to state publicly their views on abortion as a Victorian senator moves to push the divisive issue into the election campaign spotlight.

Democratic Labor Party (DLP) Senator John Madigan will use a speech to the Sydney Institute on Tuesday night to provoke debate about abortion and criticise politicians he accuses of not following their conscience on the issue.

"There is a small cohort of members and senators who, when put to the test, will claim they are pro-life," Senator Madigan will tell the event, titled Integrity in Politics.

"Unfortunately, they rarely introduce adequate legislation and secretly wish it would not raise its ugly head."

Senator Madigan's strongly anti-abortion stance might gain added weight if, as speculation suggests, he ends up sharing the balance of power in the Senate after the September federal election.

Suspended Katter Party Senate candidate Bernard Gaynor used social media on Tuesday to support Senator Madigan.

He challenged politicians, including former Labor prime minister Kevin Rudd and his own party leader Bob Katter, to disclose their views.

"Will any ALP/LNP/KAP pollies open up on their positions re: abortion like DLP?" Mr Gaynor tweeted.

"Does @KRuddMP have a view on abortion?"

"Will @TonyAbbottMHR support anti-abortion campaign?

"Will @RealBobKatter back DLP senator on anti-abortion campaign?".

Mr Gaynor's KAP Senate candidacy (for Queensland) was suspended after he said in January that he wouldn't allow gay teachers to educate his children.

But his party membership has not been revoked, and Mr Gaynor is fighting his suspension.

KAP does not currently have a publicly stated view on abortion.

Mr Abbott has previously said he believes abortion should be safe, legal and rare.

Prime Minister Julia Gillard last year said Labor would always support and protect access to publicly funded abortions.