Alun Michael will bring plenty of experience to the jury room

The rural affairs minister, who represents Cardiff South and Penarth, is expected to hear cases at a crown court in London.

A recent change in the law removed MPs' exemption from sitting on a jury. Mr Michael, a former Home Office minister responsible for police and criminal justice, was the first leader of the Welsh assembly.

Before becoming an MP in 1987 he was both a youth worker in Cardiff - serving on the probation committee - and a magistrate, and is well versed in court matters

He said it was everyone's right to serve as a juror and he welcomed the change in the law introduced in April which allows police officers, lawyers, vicars, MPs and government ministers to take on the role.

It was not only important to rule out any conflict of interest but to make sure there was no perceived conflict of interest Alun Michael

"The point is that it is a responsibility of the citizen and it is now open to everyone including police, MPs and ministers," said Mr Michael.

He said he was called up for service in the jury box later this month but asked for a deferment in order to take legal guidance on its "propriety".

"It was not only important to rule out any conflict of interest but to make sure there was no perceived conflict of interest," said the minister.

"It might be that I am called to serve in a case where I have written the legislation."

Mr Michael served as a minister of state in the Home Office before becoming Welsh Secretary when Ron Davies resigned in 1998.

He also became a Welsh assembly member and then its first leader in May 1999, only to resign nine months later before facing a no confidence vote in a row over European funding.

Guidance was being drawn up on his jury duties and would be available by the time he is recalled to serve, he said.

Unremitting pressure

The opening up of jury membership follows concerns over the high numbers of people avoiding duty.

Before the changes in the 2003 Criminal Justice Act, fewer than half of the 480,000 people called up every year were eligible.

It meant that juries had disproportionate numbers of unemployed, retired and unskilled people serving on them.

Now people are excused from duty only in "exceptional circumstances" and even Tony Blair could be required to sit on a jury.

However, Mr Michael said that appeared unlikely.

"I can imagine that it would be difficult for anyone with the unremitting pressure of the PM - but I think it is something that is theoretically possible," he said.