Jill Kirby: We need more politicians with outside experience - and that means being grown-up about MPs' expenses

Isn't it time we started trusting our MPs a little more? Last week the Telegraph reopened its expenses war on politicians by revealing that some of them use their second home allowances to rent flats from other MPs. Its columnist Matthew Norman described this as a taxpayer-funded wealth creation scheme and suggested MPs should live in barracks instead. Matthew Sinclair of the TaxPayers' Alliance, always on hand to give our elected representatives a kicking, thinks that MPs who buy first class train tickets in advance, for less than the price of an open standard ticket, should instead be looking for cheaper second-class deals. I'm all for cutting wasteful public spending but I think Sinclair has the wrong target here. He should concentrate his fire on the expenses lifestyle of our vastly overpaid MEPs, whose gravy train makes Westminster expenses look like a bargain.

On most long-distance UK train routes, second class carriages are so crowded and noisy that it's very difficult to get any work done. In fact on some trains you can barely get your laptop open, the space between the seats is so tight. I long ago gave up trying to do anything more demanding on a train than read a good book. But then I don't have a constituency to visit every weekend. I certainly don't begrudge MPs the price of a first class ticket to get to their constituencies, since I think it very likely that they will be usefully employed for most of the journey. Do the above-mentioned indignant Matthews think our elected representatives are lounging amidst the starched white linen of a first-class dining care, clicking their fingers at the wine waiter or taking a post-prandial snooze? Travelling first class is not about glamour or status any more, it's just a kind of mobile office.

Nor do I think we should work ourselves up into a lather of righteous indignation about MPs' London rental arrangements. Those with constituencies outside London are expected to maintain two homes, in order to accomplish both their parliamentary duties and their constituency obligations. As long as an MP claims expenses for only one of those homes, I don't see why it should concern taxpayers if he or she is renting a property to - or from - another MP. Speaker John Bercow is right to resist the publication of such information: what business of ours can it possibly be? In any case, what could be more sensible than to rent a flat from someone you know?

Taxpayers were quite rightly revolted by the way in which MPs managed to stretch the definition of maintaining a second home to cover duck houses and dog food. But I do not think that gives us licence to criticise them for using first class travel, or for renting a flat from a colleague.

I'm also troubled by the suggestion being floated by IPSA that MPs' pay might in future be varied according to whether or not they have outside earnings, with those who don't have any other source of income being paid more generously. I think MPs should be encouraged to keep working in other jobs, not penalised for so doing. The best way to keep down costs to the taxpayer, whilst improving the quality of those we elect, is to let them go on working outside Westminster.

Many people with professional qualifications and established careers, such as doctors, accountants or lawyers, for example, can make extremely effective MPs, drawing on their training and expertise to improve legislation, conduct enquiries or hold the executive to account. Entrepreneurs and company directors have experience of growing or managing a business, leading a team and coping with financial and regulatory pressures. For them, fiscal policy is not just economic theory. Yet most successful professionals, and many business people, will have earning capacity well in excess of £65,000 a year. Becoming an MP is unlikely to hold many attractions for them, requiring them to sacrifice not just their income but also their privacy. Yet it is in all our interests to encourage them to enter Parliament, where they will be of far more use than a bunch of ex special advisers and policy wonks.

So why don't we make it clear that we expect MPs to continue to spend some of their time working in their previous professions, and maintaining an additional income, rather than frowning on the habit? Rather than tut-tutting about second jobs, we should concentrate on selecting candidates who have already shown their ability to create a career outside politics. Only on becoming a minister should it be assumed that an MP has insufficient time to hold down another job. At present, according to IPSA, fewer than 70 (of 650) MPs have outside earnings. That suggests hundreds of MPs have far too little contact with the world outside Westminster. Let's make it easier, not harder, for them to reduce their dependency on the public purse. And then perhaps we could spend fewer column inches chewing over their housing arrangements or preferred mode of transport.