Why are we asking this now?
MPs have controversially devised a scheme that allows them to claim £25 a night in "subsistence", when staying away from their designated main home. The allowance is close to double the previous £4,800-a-year limit for unreceipted claims, and comes despite public outrage – recorded vividly in last week's Norwich by-election – at the whole of the political class for their apparent grasping for taxpayer's money.
So what's changed exactly?
Under the old regime, MPs could claim a maximum of £24,006 under the Additional Costs Allowance. This covered things like mortgage interest payments on second homes, utility bills and council tax. They could also claim up to £400 a month for food, while for furniture and furnishings the maximum for each item was set by the so-called John Lewis list.
Under the new regime, they can no longer claim for furniture and furnishings, or for food, but can claim up to £24,222 for "personal additional accommodation expenditure" plus mortgage interest of up to a maximum of £1,250 a month. Utility bills and council tax – and a new daily subsistence rate of £25 per night – can also now be claimed. Sceptics argue that most of the changes are cosmetic in nature, and that the refusal of Parliament to push through more radical reforms shows how out of touch the main parties are with public feeling.
Why this figure of £25 a night?
The advantage of a flat rate is that it takes away MPs' incentive to book themselves into the most expensive hotel they can find. On the other hand, if someone puts an MP up for nothing, they can legally claim £25 and pocket it.
What has Parliament done in response to the expenses scandal?
The Prime Minister pushed through the Parliamentary Standards Bill, setting up an independent body to authorise MPs expenses. But plans for a legally binding code of conduct were dropped because of widespread opposition among MPs, prompting accusations that they're still looking after themselves. The original plans would also have created two new criminal offences for MPs, one a ban on paid advocacy and the other relating to rules for the registration of interests. They were dropped, though it will be a criminal offence for an MP to submit bogus expenses.
The House of Lords successfully prevented any of the new regulations from applying to them.
Why are disgraced MPs still allowed to sit in Parliament?
There is no mechanism for forcing an MP to resign his or her seat before an election, unless the MP has received a jail sentence, has accepted a paid office from the Government, or is certifiably insane.
Voters can call on their MP to resign but the MP is not required to take any notice, and by hanging on until an election, they can claim they qualify for more than £60,000 in redundancy and grants for winding up their offices. They don't get this money if they resign during a Parliament.
Have any MPs resigned in the wake of the expenses furore?
Michael Martin gave up his seat after he was forced to resign the Speakership because there is a place waiting for him in the House of Lords. The only MP who genuinely forfeited his place in Parliament was Ian Gibson, the Labour MP for Norwich North, who arguably was not the worst offender – just the offender with the greatest sense of honour. In last week's by-election in the constituency, 27-year-old Chloe Smith became the youngest member of the Commons after securing a 16 per cent swing to the Tories.
But haven't other MPs promised to resign?
Former Communities Secretary Hazel Blears resigned from the Cabinet after Gordon Brown descrived her tax arrangements as unacceptable. A cluster of MPs have said they will go at the next election, but are hanging on to make sure they pick up their salaries. Three Labour MPs – Elliot Morley, Margaret Moran and David Chaytor – have no real choice because the Party won't allow them to stand as candidates again, after they were hauled in front of a specially convened star chamber.
A number of Tories are also standing down because of the furore. They include Andrew MacKay – a former confidant of Conservative leader David Cameron – who was roasted at a public meeting of his Bracknell constituents. His wife, Julie Kirkbride, had also said she would stand down because of the reaction of her Bromsgrove constituents, but is having second thoughts. More than a quarter of the Tories' 196 MPs are retiring, though not all because of the expenses scandal. Of the three main parties, the Liberal Democrats appear to have been least tainted, in part because they have fewer MPs. Fringe parties such as the BNP capitalised on the anti-incumbency feeling in local elections last month.
Have any of the culprits actually paid back some money?
Last month, parliamentary authorities released figures that showed 182 MPs from all parties had repaid a total of £478,616 that they had claimed since 2003. The biggest single repayment was £42,674 by the Labour minister Phil Hope, who had been particularly upset by the way his voters reacted to his expenses claims.
Morley, who carried on claiming after his mortgage had been paid, has repaid £36,800. Barbara Follett, wife of the millionaire author Ken Follett, repaid £32,976, most of which was for private security at her London home which she had installed after being mugged. Gordon Brown and David Cameron also paid back relatively small sums.
Why should MPs be allowed to claim so much money anyway?
An MP's job is unlike almost anybody else's, in that they are expected by their electors to live in or near their constituencies, but must also spend a large part of their working life in Westminster. It seems reasonable, therefore, that MPs with seats outside London should have one home subsidised by the taxpayer.
What has shocked the public is the freedom they have allowed themselves, as manifested in some of the more outlandish claims. These include a house on a duck island, bills for the clearance of a moat and refurbishments for servants' quarters. And there were other claims for homes miles away from both London and the MP's constituency.
What happens next?
Sir Christopher Kelly, formerly a senior civil servant and now chairman of the Committee on Standards in Public Life, is holding hearings at the moment and will release his final report in October. It will make recommendations for specific reforms stipulating exactly what MPs can claim for. It's unlikely that he will include the cost of watching porn movies late at night, as former Home Secretary Jacqui Smith's husband Richard Timney confessed to doing.
So have MPs finally learned their lesson?
* Scores of MPs are stepping down from Parliament at the next election
* A new Parliamentary Standards Bill has established an independent body to authorise MPs' expenses
* The recommendations of Sir Christopher Kelly's committee on expenses will be implemented after it reports in October
* The new Green Book allows MPs to charge £25 in overnight expenses without submitting a receipt
* MPs are merely staying on until the next election in order to secure their payoff
* The Parliamentary Standards Bill was watered down before being passed by the Commons