BERLIN (Reuters) - Voters in Hesse will be asked on Sunday whether they want theirs to be the last German state to abolish the death penalty.

A referendum on whether to endorse a raft of revisions to the state’s constitution is being held in parallel with a regional parliamentary vote, and politicians hope finally to bring to an end a decades-old anomaly.

Like all European Union members, Germany has banned the death penalty and it is enshrined in the national constitution, its Basic Law of 1949.

But the constitutions of some states, such as Hesse, predate the Basic Law. All but Hesse have since introduced local bans. But one of Germany’s wealthiest and most populous states has yet to follow suit: an embarrassment for a country that is an outspoken opponent of capital punishment.

“Partly it was never modernized because it wasn’t necessary - the Basic Law overrules state constitutions,” said Juergen Banzer, a Christian Democrat who served on the committee of churches, trade unions and community organizations that drafted the amendments.

But there was another reason: Hesse is the only state where constitutional amendments need to be put to the people. The one thing more embarrassing than the lack of a death penalty ban would be a vote to ban it that failed.

“There was a fear that if a terrible crime was committed just as Hesse voted on whether to abolish the death penalty, then the vote could go the wrong way,” Banzer said.

The death penalty abolition is one of 15 amendments to be voted on, including statements on children’s rights, sex equality, European unity and environmental sustainability.