Former MP Eric Illsley has been given a year's jail sentence for dishonestly claiming parliamentary expenses.
Illsley, 55, pleaded guilty to £14,000 of expenses fraud last month relating to claims he made for his second home between 2005 and 2008.
He becomes the second former MP, after once Labour colleague David Chaytor, to be jailed for expenses offences.
Mr Justice Saunders said Illsley had breached the "high degree of trust" placed in MPs by the public.
His jailing came on the same day as former Labour MP Jim Devine was found guilty on two counts of dishonestly claiming £8,385 of expenses by using false invoices for cleaning and printing work. Devine has yet to be sentenced.
Illsley pleaded guilty to three charges of false accounting, admitting to dishonestly claiming payments for insurance, repairs, utility bills and council tax at his second home between 2005 and 2008.
Passing sentence in Southwark Crown Court, Mr Justice Saunders said Illsley received £100 more a week on average than he was entitled to over a three-year period.
Illsley bore a "small but significant" responsibility, he added, for the decline in public trust in Parliament which had occurred as a result of the abuse of expenses by a number of now former MPs.
"The commission of the offences which came to light as a result of the police investigation into parliamentary expenses has tarnished the reputation of politicians and Parliament," he said.
"These offences were committed in breach of what was the high degree of trust placed in MPs by the authorities in the House of Commons only to make honest claims. It is vital that people feel able to trust our legislators and their use of public funds."
He received a shorter sentence than Chaytor, who is is serving an 18-month jail term after pleading guilty to making bogus claims.
Mr Justice Saunders said Illsley's offences were less serious as they involved smaller loss to the public purse and Illsley had not created "false documents to support the claims".
Illsley has apologised for his conduct and said he "deeply regretted" his actions.
His lawyers had asked for a suspended sentence, acknowledging the publicity surrounding the case had "shamed" Illsley but arguing he was a "good man".
"Mr Illsley accepts that, for this case, a sentence of imprisonment is inevitable," William Coker QC, acting on Illsley's behalf, told the court.
"These convictions have, of course, ruined him. At his age, he sees very limited opportunities to make something of his life but he accepts, as he must, that ruin is what he deserves."
Illsley stood down as an MP before sentencing, his resignation triggering a by-election in the Barnsley Central constituency which he represented.
He was re-elected as a Labour MP last May, having first entered Parliament in 1987. He was suspended by Labour after being charged last year and subsequently sat as an independent.
Last month, Lord Taylor became the first member of the House of Lords to be convicted in relation to expenses fraud.
The former Conservative peer was found guilty of making £11,277 in false expenses claims in relation to travel costs between his Oxford home and Westminster and for subsistence for staying in London.