The chief inspector of prisons, Sir David Ramsbotham, has put himself at odds with Labour and Conservative politicians by backing a campaign to give voting rights to prisoners.

His comments follow an unsuccessful high court case by three prisoners under the Human Rights Act.

The ruling was welcomed by the Home Office, which argues that prisoners "forfeit" the vote when convicted of a crime.

Speaking on GMTV's Sunday Programme Sir David argued that the vote ban was an obstacle to prisoner rehabilitation.

"They have had their liberty removed as punishment but they are still citizens of this country. If you are trying to encourage them to be responsible citizens when they come out, you have to encourage that responsibility by giving them as much as you can," he said.

Prisoners have the vote in 19 European countries but have been denied voting rights in the UK for over a century.

Ruling last week, judges said that legislation was required to overthrow the ban.

Making his ruling lord justice Kennedy said: "Parliament has taken the view that for the period during which they are in custody convicted prisoners have forfeited their right to have a say in the way the country is governed."

Shadow home secretary, Ann Widdecombe, has described votes for prisoners "as darned silly" and argued that such cases brought under human rights legislation bring "the law into disrepute and makes a mockery of justice".

"The idea of prisoners voting is darn silly. The courts have ruled that convicted prisoners, many of them dangerous, cannot be allowed to take part in normal society. How therefore, can it be sensible to give them a say in how that same society should be run?," she said.

Reform has the backing of Prison Service director general Martin Narey and the Conservative peer Lord Hurd, but with such unusual unanimity between Labour and Conservative and in the run-up to a crime-busting general election change is unlikely in the foreseeable future.

Joe Levenson of the Prison Reform Trust, the organisation which backed the high court case, has welcomed Sir David's comments.

He believes that giving prisoners the vote would aid rehabilitation and force politicians to take prison issues more seriously.

Condemning what PRT regard as a "relic of the 19th century" he said: "Disqualifying a drink driver has logic but taking a way a prisoners right to vote makes no sense."