As reported in later editions of last night's Evening Times, the Glasgow-born ex-MP had previously pleaded guilty to false accounting by filing 19 fake receipts for "research and translation" services.
Sentencing MacShane at the Old Bailey yesterday, Mr Justice Sweeney said the former Europe minister had shown "a flagrant breach of trust" in "our priceless democratic system".
MacShane said "Cheers" as the sentence was delivered, before adding "Quelle surprise" (French for 'what a surprse) as he was led from the dock.
His guilty plea followed more than four years of scrutiny into his use of Commons allowances.
The offence of false accounting covered 19 "knowingly mis- leading" receipts that MacShane filed between January 2005 and 2008.
The 65-year-old used the money to fund a series of trips to Europe, including one to judge a book award in Paris.
The court heard that MacShane incurred "genuine expenses" but chose to recoup them by dishonest false accounting rather than through legitimate claims.
The judge said he had considered a number of mitigating features, including MacShane's guilty plea, and that the offences were "not committed out of greed or for personal profit".
Following sentencing, a former Labour minister said MacShane should not have been jailed as he has already suffered enough.
Former transport minister Tom Harris, said: "I think it is very disappointing that the judge decided to treat him as MPs who had gained personally from their fraudulent activities.
"Denis is not in the same category. He made no personal gain. He was forced out of Parliament, he had to give up his seat and I think he has suffered enough.".