Former MP David Chaytor out of prison

David Chaytor has been released from prison after serving just a quarter of his 18-month sentence (Reuters)

The first former MP jailed over the parliamentary expenses scandal has been released from prison after serving just a quarter of his 18-month sentence, sources said.

David Chaytor spent four and a half months behind bars after admitting he fiddled his parliamentary expenses to falsely claim more than £22,000 of taxpayers' money.

It is understood that the ex-Labour MP for Bury North was freed from Spring Hill Prison, near Aylesbury, Buckinghamshire, under the home detention curfew scheme, which allows non-violent prisoners who pose a low risk to be tagged and released early.

Chaytor, 61, became the first former MP to be jailed since Tory peer Lord Archer when he was sentenced in January.

Southwark Crown Court heard that he forged tenancy documents and invoices to make fraudulent expenses claims for rent and IT work from the Commons authorities.

Passing sentence, Mr Justice Saunders told Chaytor that putting him behind bars was one of the first steps in restoring public faith in the parliamentary system.

In March the Court of Appeal rejected an attempt by the former lecturer to have his prison sentence reduced, ruling that his offences were "a grave breach of trust" that contributed to "serious damage" to Parliament's reputation.

Chaytor, of Lumbutts, Todmorden, West Yorkshire, will be on the home detention curfew scheme for the next four and a half months before spending the last nine months of his sentence on probation.

Fellow disgraced ex-Labour MP Eric Illsley, who was jailed for 12 months in February, has already been released from prison.

A Prison Service spokesman said: "A home detention curfew (HDC) is available to low-risk prisoners serving sentences of more than three months and less than four years, who are deemed appropriate for early release.

"To be placed on HDC, a prisoner must have served a quarter of their sentence and have spent a minimum of 30 days in prison.

"If a prison governor thinks there is a significant risk to the public, or risk of re-offending on HDC then the release will not be granted."

Campaigners criticised the decision to release the former MP early.

Emma Boon, from the TaxPayers' Alliance, said: "Chaytor might not be considered a threat to the public, but prison isn't just about protecting society from dangerous criminals.

"It's also there to offer a deterrent to those who would commit further crimes, and it's there as a punishment.

"Given the seriousness of the offence, taxpayers will ask if this was a serious enough punishment or deterrent.

"He stole thousands of pounds from taxpayers and in doing so he seriously damaged public faith in the parliamentary system.

"Taxpayers will be rightly angry that Chaytor has served less than half his sentence."

Campaigners criticised the decision to release the former MP early.

Emma Boon, from the TaxPayers' Alliance, said: "Chaytor might not be considered a threat to the public, but prison isn't just about protecting society from dangerous criminals.

"It's also there to offer a deterrent to those who would commit further crimes, and it's there as a punishment.

"Given the seriousness of the offence, taxpayers will ask if this was a serious enough punishment or deterrent.

"He stole thousands of pounds from taxpayers and in doing so he seriously damaged public faith in the parliamentary system.

"Taxpayers will be rightly angry that Chaytor has served less than half his sentence."