Margaret Moran, of Ivy Road, St Denys, is alleged to have claimed nearly her entire annual allowance in one bogus expense entry and forged invoices for more than £20,000 of non-existent goods and services.
Moran, 57, submitted an invoice for £22,500 in August 2008 - just under the annual maximum expense allowance for an MP - to treat dry rot at her Southampton home, using the money instead to fund ''home improvements'', the jury has heard.
Moran, who served as MP for Luton South from 1997 until the 2010 general election, is accused of falsely claiming about £60,000 in parliamentary expenses between 2004 and 2008, of which she received £53,000.
Southwark Crown Court, in London, has heard that she was able to make the dry rot claim by ''flipping'' her two homes - changing which property was her second home and therefore allowing her to claim expenses on it.
She also allegedly changed dates on invoices for the work so that the money would be paid.
One invoice in August 2007 was for £14,805 - apparently for boiler repairs and work on her conservatory in her constituency home in Luton, when it was actually at her house in Southampton, the court heard.
On another fake bill for more than £4,000, address details given for a building firm were those of an elderly couple.
She also claimed more than £2,000 for a landline at her flat when there was no phone line fitted, the jury heard, and for carpet for three bedrooms for her one-bedroom Westminster flat.
Moran is accused of 15 charges of false accounting and six of using a false instrument over the claims for parliamentary expenses.
The former politician was found unfit to stand trial due to mental health issues, so proceedings are taking place in her absence.
Rather than finding her guilty, jurors have to decide whether Moran did commit the acts alleged in the charges, and whether they amount to the offences with which she is charged.
Moran altered addresses to make it look as if she was making legitimate claims for her second home or constituency office, when they were to cover her personal costs, jurors heard.
Prosecutors say Moran ''abused the scheme'', going as far as to re-submit expenses claims with different descriptions and supportive invoices if they were initially rejected by parliamentary authorities.
The former Luton South MP tried to claim £47 for printing 50 Christmas cards, but was told that greetings cards were not covered by Parliamentary expenses, the court heard.
So she submitted a new invoice for the same amount, but this time for ''printing services'', jurors were told.
The same thing happened with a claim for birthday cards, which were later described as ''surgery cards'', it is alleged.
Moran submitted a claim for £22,500 for urgent works for dry rot at her Southampton home on April 1, 2008.
Jurors heard, however, that a builder completed the work between September 2007 and March 2008 before the property became Moran's recognised second home in October 2008.
It had previously been listed as her first home after the sudden death of her sister as she became guardian to her two young children, the court heard.
James Sturman QC, defending, said the case represented ''a very, very unhappy period for British democracy'', as Moran is the final MP to face criminal charges following the expenses scandal.
''Your task is an onerous one. You have to ask if this lady, who is not here, who it is agreed by all parties is not fit to defend herself....whether she committed the offences alleged against her.''
Mr Justice Saunders told jurors they were not deciding whether Ms Moran is guilty or not guilty as she is not medically fit to stand trial.
''What you have to decide is whether she did the acts which constitute the offences,'' he said.