The quickest of glances at the Register of Members' Interests encapsulates the deepening divide over the disclosure of MPs' extra-curricular earnings. Some MPs - mostly Labour - hold no other jobs; some - mostly Conservative - have several.
One part of the Commons exists on the MPs' salary of pounds 33,189 a year; another earns far more.
Just how much, it is impossible to say for sure, and, if Monday's vote goes against disclosure, may never be known. But there are indicators.
Consultancies are worth around pounds 10,000 a year and directorships can bring in pounds 15,000. These are only averages: a directorship can be worth much more. Lucrative share options and shareholdings can also accompany a directorship.
On top of that, MPs can be paid for furnishing introductions and bringing in new clients if their employers are lobbying and public relations firms, or a bank. Then there are fees for television appearances and journalism and lecturing.
The extent of their earning power is huge: there is no shortage of businesses anxious to employ an MP. According to one recent report, 100 MPs - 88 Tories, 10 Labour and two Liberal Democrats - earn at least pounds 3m a year from their directorships. The Nolan inquiry into standards in public life revealed 168 MPs as having 356 consultancies.
Widely thought to be heading the earnings ladder are the Tory, David Evans, with his Leapsquare consultancy company; Sir Edward Heath, with his private company, Dumpton Gap, which handles payments from his lecturing and writing interests; Geoffrey Robinson, the Labour MP, who runs his own engineering firm, TransTec.
On paper, David Mellor is streets ahead of most of his colleagues, with numerous consultancies and his broadcasting work. However, as a consultant his employers are not obliged to declare what he is paid.
The same applies to those other regular broadcasters and writers, Austin Mitchell and Roy Hattersley. They, too, are generally reckoned to earn far more than their MPs' salary.Reuse content