Pensions minister Steve Webb has transformed the way we retire - and he doesn't care if we blow our savings on a Lamborghini

Steve Webb's idea of relaxing on holiday is to fill in complicated number puzzles.

But perhaps this geekiness is part of the reason why no politician has ever held this position for as long. He's been in office since 2010. Before that the job switched hands ten times in a decade.

'It was a revolving door,' says Mr Webb. 'I've had the great advantage of coming in at the start of the Parliament. Pensions is a long-term game, so you need time to see things through. In a way, this is the perfect job for me. You've got the social, human side of how pensions affect people's lives, and then all that lovely technical detail.'

If you must: Steve Webb (right) said people should feel free to buy a Lamborghini with their pension savings.

While many politicians talk big and achieve little, you'd be hard pressed to level that accusation at Mr Webb.

In the past four years he has overseen the introduction of a new flat-rate state pension of £144 a week, promised a so-called triple-lock on how much it will be increased by every year (it will rise by the greater of inflation, wages or 2 per cent), and launched an automatic enrolment programme to get ten million workers a company pension for the first time.

Most recently and dramatically, he was the man behind the Budget's revolutionary shake-up that will allow everyone the right to take their pension as cash, and avoid being ripped off by taking an income for life - an annuity.

He's not finished yet. By the next election he wants to bring in a new type of pension - called defined ambition - that will ensure everyone gets out at least what they paid in.

The MP for Thornbury and Yate in Gloucestershire, he spends four days a week in Westminster, staying in a flat near the office.

'In many ways yesterday was a very typical day.' he says. 'I get in at 7.30 am, then have a cuppa and a slice of cake for breakfast.' Cake?

'Yes. I've got a terribly sweet tooth. Bakewell tart today. I'll have cake for elevenses, too.'

Then it's back-to-back meetings - he'd just met the head of the insurance industry trade body who'd been giving evidence to a committee of MPs. Afternoon is spent in Parliament, and then the evening at his office in the Commons answering queries from constituents.

Back at home he attends church every Sunday. Wife Helen is an ordained minister and they help out at a local breakfast club. She also volunteers for a pregnancy charity.

Before being elected as a Lib Dem MP in 1997, the 48-year-old studied Philosophy, Politics and Economics at Oxford University, then worked for the Institute of Fiscal Studies, specialising in research on taxes and benefits. He was appointed pensions spokesman in 2001.

But fate landed him the ministerial role. Conservative pension spokesman, MP Nigel Waterson, lost his seat in the General Election to a Lib Dem. Steve Webb was the logical, and only, choice.

'It's actually Iain's 60th birthday today,' remembers Mr Webb. 'I didn't send him a card, which is remiss of me. It's not a political statement, I forgot to send my goddaughter one recently, too.

'I respect the fact that as an ex-leader of the Conservative party, he could have just gone off, not had any other grief or hassle and been a director of a dozen firms and had an easy life. But what does he do? He sets up a think-tank and devotes himself to social reform of the benefits system. You've got to respect that dedication. It helps that we've been working together for four years now.

'Do I understand why they feel angry? Absolutely I do, partly because they think that if they retired in April 2016 they would get £144, when actually they wouldn't on average.'

This is because they would not have contributed enough National Insurance.

Mr Webb says he is sympathetic because they didn't know their state pension age was changing, as this was a change made two decades ago - though not made widely public at the time.

There are more things he would clearly like to get his teeth into. The Lib Dems want to reform tax relief on pensions.

Currently putting £1 in a pension costs a basic rate taxpayer 80p, but 60p for a higher rate taxpayer and just 55p for a top rate payer. He'd rather have a flat benefit for all - and likes the idea that £1 should cost everyone just 70p.

And he has his eyes on the lifetime allowance on pensions. Currently anyone with more than £1.25 million in a scheme gets hit with a 55 per cent tax charge.

He says: 'The lifetime allowance is a funny thing because it doesn't just say if you pay in more than this you don't get tax relief, we actually have a penal rate of tax. To actually say that we will punish you if you go beyond our limits seems illiberal to me.'

His two children are teenagers. So what kind of pension does he think they'll end up with?

'It won't be a final salary scheme, but I've made it much more likely that there will be a state pension when they retire. It won't be a king's ransom though.

'And there won't be such a thing as retirement day as such. They'll be in second jobs, third jobs, part-time work.

'It'll be much more a process as each generation is working longer. It'll just be a different culture. The days of the gold watch retirement day are probably over.'