Can it really be that hard to submit an expenses claim?

Oliver Wright meets Ipsa boss Andrew McDonald – and puts his own receipts through the system

It's 9.30am and I'm in an office block near Westminster pretending to be an MP claiming his expenses. In front of me is a computer and to my right a crumpled pile of receipts for newspapers, chewing gum and a rather expensive lunch.

Sadly this is 2011 – so no duck houses (Peter Viggers), chimney sweeping (Douglas Alexander) or extendable shaving mirrors (Julie Kirkbride) are allowed.

In fact Phil – who is guiding me through the process – looks askance at how much I spent on chewing gum. He hasn't seen the lunch bill yet.

The screen in front of me is the online claims system which every MP now has to use to get reimbursed for all their expenses, from accommodation to staffing to office equipment.

I am trying it out after an interview with Andrew McDonald, chief executive of the new – and thoroughly hated – MPs expenses watchdog Ipsa (the Independent Parliamentary Standards Authority).

Mr McDonald had told me the system is straightforward. It certainly looks simple. Claimed items are colour-coded green (submit), red (rejected), and pink (pending). Drop-down menus are all the rage and it has the capability to check the basics of expense claims before they are submitted.

The first problem is that there is no category in the drop-down menu for either newspapers or lunch. Phil explains that it would come under the "other" category. I then have to fill in four blue boxes for description, date, reason and price. A message appears: "Please ensure you explain why the expense is required for the performance of Parliamentary functions." Phil reassures me that this is a standard message and to ignore it.

Right.

Since it came into operation, Ipsa has trained hundreds of MPs and their staff on how to use the system – and claims that they now mostly like it. One wizened MP enjoyed it so much he has since taken up internet banking, apparently.

This comes as a surprise because as any journalist working in Westminster will tell you, Ipsa is one of the few subjects which unites MPs on both sides of the house. Disgraceful, useless, hopeless – just the more printable descriptions of the authority in the past few weeks alone.

"Unless Cameron gets rid of Ipsa in April there is going to be a revolt," said one particularly irate minister. "It is as simple as that." Such strength of feeling has not escaped Mr McDonald, who took up his post in September 2009 and has built up Ipsa from scratch. But he insists that things are not that bad.

"Some MPs have expressed vigorous views to me, that's certainly the case," he says euphemistically, "and not everybody in Parliament is full of admiration for everything that Ipsa does. But there has undoubtedly been a shift in the right direction. There is less tension in those relationships than there was early on."

Mr McDonald is in a difficult position. If the public is vengeful after the expenses scandal then Ipsa is expected to be its angel, cracking down on "freeloading" MPs living it up on the taxpayers' expense.

But Ipsa has an obligation to MPs as well. It is easy to forget that they have overdrafts, family commitments and (even) feelings like everyone else. They also have a job which requires long and anti-social working hours.

How would anyone feel, MPs ask, if told they had to pay thousands of pounds out of their own pocket just to have some semblance of a proper family life with their children? It is a balancing act which, Mr McDonald admits, Ipsa has not always got right.

"I absolutely understand there are some very strong views held by a number of MPs about Ipsa. We take that very seriously and put a lot of time into understanding the views of MPs as well as those outside parliament."

It is "quite clear", he says, that the system of cash advances and loans "did not hit the mark... They were not what MPs wanted and were not taken up in great numbers. That has put more pressure on MPs and has been one of the sources of tension. We need to learn from that."

Mr McDonald is a career civil servant and talking to him there are touches of Sir Humphrey's famed delivery that one can imagine infuriate some of the more restless Jim Hackers in Westminster. Asked, for example, how he responds to Mr Cameron's threat that Ipsa has until April to sort out the expenses system, or he will intervene to sort it out himself, Mr McDonald replies: "I think it's really important that Ipsa focuses on its core responsibilities as a regulator and as a service provider where Ipsa takes a view about what is appropriate in terms of balancing its responsibility to the public as a whole to ensure that it gets the right balance in terms of building and developing a system of expenses which is in the broader interests of the UK and supports our parliamentary democracy."

So that's clear then.

It does seem likely that large concessions on travel, second homes and taxis are on the cards. He is franker about mistakes made and shows a genuine resolve to somehow square the circle of what MPs want and what the public expect. "This has been in all sorts of ways – and here I am going to use a deliberate euphemism – a fascinating role," he says.

"There has been one challenge after another to overcome. One of the things we have done a lot of work on recently is getting a fuller understanding of how MPs go about their role – spending time with them in their constituencies as well as at Westminster. We need to be listening to a broad range of views."

He says, perhaps surprisingly, that he really enjoys the role.

"I may be stretching your credulity but I really love this job. I've a real zest for this. This is not a job for somebody who wants a shortcut to popularity – I fully acknowledge that. But in an old-fashioned way I really do think there is a public good to be realised here. I can genuinely say it is the most rewarding job I have ever had."

Back to my expenses. After a few mistakes – and the restaurant bill would have been turned down anyway I discover unless I proved it was "vital" for my Parliamentary work – I manage to get it to the stage where it could be submitted and scrutinised.

So is it as bad as the MPs say?

For anyone brought up on the internet it's not hard to master. But it is bureaucratic, time consuming and perhaps unnecessarily fussy about the evidence it requires for even the smallest transaction. But that, some might say, is the price MPs have to pay for what they did in the first place.