People will find it harder to avoid jury service from today, and the Government is promising major changes to simplify the criminal justice system.

Under the new rules, if you get a jury summons and can't make it, you will have to do jury service at a more convenient time within 12 months.

The move is just one of a number of big changes to the criminal justice system designed to make its processes quicker and more efficient.

Justice Minister Simon Power said they include raising the threshold for a defendant electing to have a jury trial.

At present, the crime must be punishable by three months' imprisonment or more - which is most crimes.

Other changes will include looking at what could be inferred by a defendant's failure to appear in court, a hint that a guilty plea may be assumed.

And there could also be limits on "alternative pleadings" - where someone charged with assault can claim that they were not there, but if they were, then the act was self-defence.

Mr Power is also expected to announce this week plans to make name suppression harder to get.

Last night, he said the changes to the jury rules were "a component part of a much bigger piece of work".

"It is designed to get justice done more swiftly because timeliness is one of the key components of delivering good justice, but we have to be mindful of defendants' rights."

Most people summonsed for jury service are excused because the time specified is inconvenient to them personally or to their work duties.

As well, a large number don't turn up at all.

Mr Power said he had "a very high degree of confidence that people do want to do their civic duty and serve on a jury".

"It's just that the way the current arrangements are in place does not give them the flexibility to make decisions at four weeks' notice about whether it fits," Mr Power said.

If they were given 12 months' notice and effectively selected or negotiated the time, it would be a lot easier to fulfil their duty to serve.

Under the new regime, being excused from jury service will be the exception rather than the rule.

Mr Power said a large body of work on the criminal justice system would cut waiting times for a jury trial in the High Court from the present 16 months and in the district court from the present 13 months or so.

The work was started by the last Labour Government, "but when I got hold of it I saw the potential in it and we have really driven it".

Mr Power said he expected to be able to make decisions in two or three weeks about what information on jurors could be given to trial lawyers.

The review follows the revelation that a female juror hearing a kidnap case in August was contacted by the defendant, convicted murderer George Baker, part-way through the trial.

He allegedly got her contact details from the list of jurors' names, occupations and addresses supplied to both the Crown and the defence.

Mr Power said there would be change, but he was considering the detail.

* 358,865 summonsed.
* 221,032 excused.
* 81,372 failed to show.

* 348,006 summonsed.
* 222,519 excused.
* 70,394 failed to show.