To travel fastest in politics, it’s often best to travel light. David Cameron was hardly overburdened with policy commitments or ideological baggage when he became the most fresh-faced Tory leader in modern history. But it was seeing the man briskly walking down Witney high street that brought this thought to mind.

Whereas the most junior minister in the Department of Work and Pensions more often than not will arrive for meetings with a team of civil servants and advisers, the man most people believe will be Prime Minister by next summer races around his constituency with just two young women for company.

And even in these days when all politicians are held in lower esteem than estate agents and journalists combined, Mr Cameron likes to get around on foot.

“Let’s walk,” he declared, as he emerged from the Witney Country Market last Friday to head for his next appointment, accompanied by press secretary Caroline and Hannah, from his constituency office.

His wallet may perhaps have felt a touch lighter, having just announced that he would be paying back almost a thousand pounds after taking a closer look at his expenses claims.

But putting your case “before the court of public opinion” is a favourite Cameron saying.

So it was always going to be interesting to see whether he was in line for a roasting from his constituents over the money he had claimed to clear a chimney of wisteria in his west Oxfordshire home and for “an inadvertent error” in his mortgage claim.

There was no doubt the walk across Witney would tell him in the clearest and most instant way whether the pensioners, mums pushing buggies and shoppers accepted their MP’s own highly publicised act of atonement?

He emerged unscathed. If anything, his walk in the morning sunshine had only brightened his mood by the time he arrived at West Oxfordshire District Council’s offices in Wood Green for a meeting with the council cabinet.

Yet surely the wisteria business must have entangled him in the “politicians, they’re all the bloody same” line of thinking. The Tory leader shook his head. “Today I walked straight across the town. All I faced was people being friendly, approachable and wishing me well.

“People are angry with politicians and parliament, there’s no doubt about that. But locally, in terms of explaining what I did and why, I think I have had a reasonable reception. I’ve always had a good and happy reception here.”

When David Cameron first invited The Oxford Times a couple of months ago to join him ‘on the road’ in his constituency, it had been a very different political world. Back then the collapse of banks and the threat to western capitalism had occupied us, rather than flipped second homes, moats and duck islands.

One of the few things not to have changed is the Conservative lead in the opinion polls. Another is the need for even the Leader of Her Majesty’s opposition to get back to his patch to visit industrial estates and hear the multitude of problems that his constituents bring to surgeries. Last Friday morning, Mr Cameron was to be found meeting traders at the Witney Country Market, where he enthusiastically inspected the food produce before being presented with a hamper. Ten hours later he was still shaking hands, having been the guest speaker at the Swerford Parish Assembly.

Given the fact that Mr Cameron hardly needs to chase votes in this rock-solid Tory seat and that he has two young children at home, you wonder what takes him to a village hall in deepest west Oxfordshire at 8pm on a Friday night.

It also meant a late drive back to London, with his family in the capital rather than their home in the constituency.

“I have a constituency with 85 rural parishes and over a 100 villages, hamlets and settlements,” he told me on the way from the council meeting to an award presentation. “Somewhere like Swerford can feel left out. And I bet someone will ask a question that will spark a thought that will have a wider application.

“Constituency work is the bit that anchors you in terms of the political work you do. Everyone thinks this constituency is rural and prosperous. But it brings up a lot of very diverse problems, whether it is to do with the child support agency, flooding or housing problems.”

But it must mean sacrificing time with his family. “There is a lot of pressure in my work life but I try to get a good balance. Tonight I will get home for supper with my wife. It will be a late supper but I will do that.

“I think it is possible to be a good leader of the opposition, a good constituency MP and a good husband and father. But it does mean you have to have clear rules such as having a night every week when I get home to help at bath time. It is important that I take the children to school at least once a week, sometimes on my bicycle, sometimes not, and I try to keep a good portion of weekends free. Luckily Nancy and Elwen, being the age they are, now delight in summer fetes. So this year I will be opening more fetes than ever before.

“I try not to beat myself up about it. You just have to find the time. When it comes to nativity plays and school assemblies, I am determined to do the same things that other dads do.”

His reflections on family life are interrupted by Caroline his press officer. His mid-morning meeting with David and Brenda Curill, whose business, Medoris, is a small healthcare firm on Witney’s Crawley Mill Industrial estate, had focused on the challenges facing small companies bidding to secure NHS contracts. At the Witney Lakes Resort, he would be lunching with Witney Chamber of Commerce, having first presented the Young Student of the Year Award to Leanne Lynas, of Abingdon and Witney College.

A two-minute chat with her was sufficient to allow Mr Cameron to deliver a touching speech, highlighting the student’s success in overcoming dyslexia, to secure a place “at one of the country’s best universities” Oxford Brookes, where she would be reading fine arts.

“Fine art graduates are beautiful and wonderful things. I know because I married one,” he told guests. Mrs Cameron had apparently taken a degree in Fine Art at the University of the West of England. She had begun painting and drawing, he added, but had gone on to design “the most expensive handbags known to mankind”.

Watching Mr Cameron touring the tables shaking hands, it was difficult not to contrast such relaxed ease with another Tory leader Edward Heath, who was known to sit through entire dinners without even talking to the person placed next to him.

Before the desserts had appeared, the four of us were heading back into Witney for a drop-in business surgery, where he heard views of people ranging from the chief executive of Blenheim Palace to a small restaurateur “living her dream” in Chipping Norton.

Discussions covered bank loans, tourism and VAT. But we all know the type of bills that top the news agenda these days and, sure enough, outside television cameras were waiting to give Mr Cameron the chance to hit out at the heavily censored publication of MPs’ expenses. “The sea of black ink” had further damaged parliament’s reputation,” he began, before insisting that “sunlight is the best disinfectant”.

But as a party leader, had he not known long before of the abuses going on, I asked him.

“I was conscious of it. That is why I never claimed for gardening, cleaning, decorating, patio heating, furniture or food. I was not , however, aware of just how bad the situation was. MPs are paid £65,000 a year, like headteachers or chief inspectors and there they have a generous allowance system. I did not think it necessary to claim for these extra things.” So why had he just repaid almost £1,000? “The expenses I chose to pay back were 100 per cent within the rules and agreed by the funds office.

“I think paying back money is a good thing and part of the atonement process that all MPs need to go through.

“The people who most infuriate the public are those who say, ‘I did nothing wrong. I was obeying the rules and therefore I’m going to do nothing about it.’ It is always going to be known as the wisteria bill. But if you look at the bill, it was all about the maintenance of the property. The wisteria had to be removed because the chimney was not operating properly. If the chimney was not operating properly, you could not light a fire and if you can’t light a fire you cannot keep warm.

“I only ever charged for mortgage interest and this one maintenance bill.

“But will expenses dominate the next election? I don’t think so.

“Three things will be there: the broken economy, the broken society and the broken political system. Expenses are just part of that.”

Mr Cameron returned into the council office building for a meeting with councillors and the South Central Ambulance Trust, about the trust’s failure to respond to call-outs quickly enough in rural areas of the county.

“We will keep banging away. There is a national target and everyone should have it. That should go for rural as well as urban areas,” he said afterwards.

There was no sign of him running behind time when, after his normal surgery, he headed off to Witney Swimming Club to present another award, this time marking the club’s new Swim 21 accreditation.

By the pool side, he posed and chatted with dozens of swimsuited children.

“Go and stand next to him,” one proud father shouted to his daughter. “He is going to be Prime Minister.”

Slapping his hands together, Mr Cameron headed for the door with the words: “So now we’re all off to Swerford.” The worrying thing for Gordon Brown is that he really did seem to be looking forward to it.