Topeka — The political battle over control of the Kansas Supreme Court will kick into high gear next week when four former governors go on a three-city tour urging voters to keep partisan politics out of judicial retention elections.

Former Republican Govs. Bill Graves and Mike Hayden will join Democrats Kathleen Sebelius and John Carlin in a series of invitation-only events in Kansas City, Mo., Topeka and Wichita.

On Friday, however, conservatives in the Kansas House, who want to oust four justices who are up for retention this year, launched what might be called a pre-emptive strike, sending out emails that denounce the news media for what they say has been biased coverage of the retention elections.

“The Kansas media’s mission to disparage conservatism and propagate liberal ideals never ceases,” stated the email from the Kansas House Republican caucus. “They’re essentially the Democrat party’s public relations team, beating a constant drum against common-sense conservatism while utterly failing to hold their liberal comrades to any semblance of accountability.”

Conservative groups are actively campaigning to remove four of the five justices who are up for retention: Chief Justice Lawton Nuss and Associate Justices Carol Beier, Dan Biles and Marla Luckert.

The fifth justice on the ballot, Caleb Stegall, was appointed to the bench by Gov. Sam Brownback, and conservative groups are campaigning in favor of his retention.

Earlier this year, the state committee of the Kansas Republican Party adopted a resolution endorsing the ouster of the four targeted justices, but GOP officials say the party itself is not putting any money or campaign resources behind that effort.

Conservatives have been upset with the court for more than a decade, dating back to the 2005 school finance decision in the case Montoy v. Kansas, in which the court ordered the Legislature to add hundreds of millions of dollars each year to the school funding formula.

Later this month, the court will hear oral arguments in yet another school finance case in which plaintiffs again are seeking upwards of $500 million a year in additional school funding.

Conservatives have also been critical of the court over a series of death penalty cases in which the court overturned the death sentences of several convicted killers, most notably Wichita brothers Jonathan and Reginald Carr, who were convicted of a grisly mass murder in December 2000.

Brownback used that issue in his 2014 re-election campaign, arguing that Democrat Paul Davis would appoint more justices like them. He also campaigned for the defeat of two justices who were up for retention that year, Eric Rosen and Lee Johnson, who narrowly survived that election.

One of the groups that is actively raising money and campaigning against the four justices is called Kansans for Justice, which was organized by relatives of the Carr brothers’ victims.

But the controversy surrounding those decisions is only part of the political battle. In each of the last two legislative sessions, conservative lawmakers have tried unsuccessfully to pass a constitutional amendment changing the way Supreme Court justices are chosen in ways that would put more power in the hands of the governor.

The series of events next week is being sponsored by Kansans for Fair Courts, an offshoot of the Topeka-based Kansas Values Institute, a group that advocates for moderate and progressive policies on a variety of issues.